Cooling system circuit diagram. Purpose and device engine cooling system

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Engine device and operation

Appointment and principle of cooling system

The cooling system serves to forced allotted from the cylinder of the heat engine and the transfer of it to the surrounding air. The need for the cooling system is caused by the fact that the parts of the engine coming into contact with the hot gases are heated greatly. If you do not cool the internal parts of the engine, then due to overheating, the lubricant layer may occur between the parts and the movement of moving parts due to excessive expansion.

The cooling system can be air or liquid.

With the air cooling system (Fig. 1, a), heat from the engine cylinders is transmitted directly by airing their air. To do this, with the aim of increasing the surface of heat transfer on the cylinders and the head, cooling ribs made by casting are made. Cylinders are surrounded by a metal casing. Through the resulting air shirt is asked to the air, the cooling engine. The fan is activated by belt transmission from pulley crankshaft.

The air cooling system was used only on low power engines. The advantage of such a system is the simplicity of the device, some reduction in the weight of the engine and the convenience of service. For'omme powerful engines The use of the cooling air system meets a number of difficulties in view of the need to remove a large amount of heat and ensuring uniform cooling of all heated engine points.

The liquid cooling system with forced circulation of the liquid includes water shirts, respectively, head and block, radiator, lower and upper connecting pipes with hoses, water pump with water distribution pipe, fan and thermostat.

Water filled with water shirts head and block, nozzles and radiator. When the engine is operating, the water pump drives from it creates a circular circulation of water through a water shirt, nozzles and radiator. According to the water distribution pipe, the water is primarily sent to the most heated block locations. Passing through a water shirt of the block and heads, water is washes the walls of cylinders and combustion chambers and cools the engine. Heated water along the top nozzle enters the radiator, where, branched on the tubes on thin jetings, cooled by air,

which is seized between tubes with rotating fan blades. The fucking water enters the water shirt of the engine.

In some engines with the upper valves, water from the pump is forcibly sent to the head shirt, saddles and nozzles exhaust valvesAnd then on the discharge nozzle is given to the radiator. Cooling cylinders at the same time produced by water circulating in its shirt due to the difference in the temperature of the water in the water jacket of the block and head. The larger water from the water shirt of the block is displaced with colder water coming from the head of the head, which provides a natural - convection circulation of water (thermonymifone). With this cooling, the conditions of operation of the engine cylinders are improved.

The thermostat installed in the upper water pipe adjusts the circulation of water through the radiator, maintaining the highest temperature.

In V-shaped carburetor engines, the total water pump connected by the lower pipe with the radiator and the fan installed on the same shaft, pumps water along two nozzles and water distribution channels into the water shirts of both block sections. The heated water is discharged from the heads through the channels, usually cast in the upper lid of the block, and through the general thermostat and the upper nozzle arrives back to the radiator. On diesels, the layout of the cooling system elements is somewhat modified.

Depending on the method of compounding the cavity of the cooling system with the atmosphere, the coercive cooling system is divided into two types - open and closed. In an open system, the cavity of the upper tank of the radiator is constantly communicated with the atmosphere. In a closed cooling system that received the use on all cars, the cavity of the tank can be communicated with the atmosphere only through a special steam valve.

Fig. 1. Engine cooling systems scheme

The engine is almost identical on all machines. On the modern cars A hybrid system is applied. Yes, it is precisely that, because not only liquid is involved in cooling, but also air. They are produced by blowing radiator cells. Due to this cooling, it turns out much more efficiently. It is no secret that at a low speed of movement, the circulation of fluid does not save - it is necessary to additionally install the fan on the radiator.

Radiator fan

Let's talk about domestic cars, for example about "Lada". To ensure a better heat exchange, the engine cooling system ("Kalina), the diagram of which has a standard configuration contains a fan. Its main function is blowing the radiator cells by the flow of air when the liquid is achieved by the liquid of the critical temperature. Manage work is performed using a sensor. On domestic cars, it is installed at the bottom of the radiator. In other words, there is a liquid, which gave heat into the atmosphere. And it should have a temperature of 85-90 degrees at this point of contour. If this value is exceeded, it is necessary to carry out additional cooling, otherwise the engine will go boiling water. Consequently, the operation of the motor will occur at critical temperatures.

Cooling radiator

It serves to recover heat into the atmosphere. The fluid passes to the cells that have narrow channels. All these cells are connected by thin plates, which improve the return of heat. When moving S. high speed Air passes between cells and contributes to the rapid achievement of the result. This element contains any engine cooling system scheme. "Volkswagen", for example, is also no exception.

Above the fan, which is mounted on the radiator was considered. It produces air blowing when the critical temperature is reached. To improve the efficiency of the element, it is necessary to monitor the purity of the radiator. His honeycombs are clogged with garbage, heat exchange is worse. The air does not pass through cells, the return of heat is not produced. The result - the engine temperature increases, its work is broken.

System thermostat

It is nothing but a valve. It reacts to the temperature change in the circuit of the cooling system. More about them will be told below. The scheme of the cooling system of the UAZ engine is based on the use of a high-quality thermostat, which is made of a bimetallic plate. Under the action of temperature, this plate is deformed. It is possible to compare it with a circuit breaker used in the power supply of houses and enterprises. The only difference is to control not the contacts of the switch, but the valve that carries out the supply of hot fluid into the contours. The design also has a return spring. When cooled of the bimetallic plate, it returns to its original position. And the spring helps her back.

Cooling sensors used

There are only two sensors in the work. One is installed on the radiator, and the second is in the engine block shirt. Let's return to K. domestic cars And remember the "Volga". The circuit of the cooling system (405) also has two sensors. And the one that is on the radiator has more simple design. It is based on the bimetallic element, which is deformed by increasing the temperature. This sensor turns on the electric fan.

On vehicles of the classic VAZ series, the direct drive of the fan was previously used. The impeller was installed directly on the pump axis. The fan rotation was performed constantly, no matter what temperature in the system. The second sensor, installed in the engine shirt, serves for one target - signal transmission to the temperature indicator in the cabin.

Liquid pump

Let's go back to the Volga again. The cooling system of which contains a circulating liquid pump in itself, it cannot be easierless to function without it. If you do not give fluid movement, it will not be able to move through the contours. Consequently, it will be stagnation, Tosol starts to throw, and the motor can jam.

Design liquid pump Very simple - aluminum case, rotor, pulley drive on one side and plastic impeller - on the other. Installation is made either inside the engine block, or outside. In the first case, the drive is carried out, as a rule, from the timing belt. For example, on VAZ cars, starting with the model 2108. In the second case, the drive is carried out from pulley

Contour stove

On some cars produced several decades ago, air-cooled engines were installed. The inconvenience in this case is one thing: I had to use a gasoline stove, which "eaten" a lot of fuel. But if liquid circuits of the engine cooling systems are used, you can take a hot antimony, which is supplied to the radiator. Thanks to the stove fan, hot air is supplied to the salon.

In all cars, the stove radiator is mounted under the instrument panel. First, the electric fan is installed, then the radiator is on it, and the air ducts are suitable on top. They are needed to distribute hot air through the cabin. In new cars, the distribution management is made using it with microprocessor systems and stepper motors. They open or close the flaps depending on the temperature in the cabin.

Expansion tank

Everyone knows that any fluid is expanding when heated - increases in volume. Therefore, it is necessary for it to go somewhere. But on the other hand, when cooled the fluid, its volume decreases, therefore, it is necessary to add it to the system again. Manually do it is impossible, but with the help of an expansion tank this procedure You can automate.

Most modern cars use the schemes of cooling systems of a sealed engine. For these purposes, there is a plug-in tube on an expansion tank with two valves: one on the inlet, the second to issue. This allows you to provide pressure in the system close to one atmosphere. With a decrease in its indicator, air absorption occurs, with a reset.

Cooling systems nozzles

To protect the engine from overheating, thereby increasing the deadline for the operation of the vehicle, the effective cooling system is necessary. The upcoming study is devoted to "air-term", their device, as well as advantages and disadvantages. Having studied the proposed information, you can compare the forced air cooled with liquid to do right choice Systems.

What is attractive an air cooling engine

In a functioning motor, the temperature of the cylinders is capable of reaching 2000 degrees, whereas the mode of 80-90 degrees is considered optimally permissible. Of course, in such extreme conditions, no item will last long. In order to preserve workers fragments, the engine needs a fairly reliable cooling system. Such structures have two varieties:

system using air cooling. Here, as the protection of the working unit, air acts as the operating unit;
liquid cooling previously, in the former times was carried out by conventional water. Technical progress affected the creation of a special substance called antifreeze. Also to reduce the temperature of the motor is used toosol.

In this publication, the first variety of systems that protect the functioning engine from excessive overheating are considered in detail. This will allow the unfavorable motorist to familiarize themselves with the device and principle of work of a complex technological mechanism.

Functions of cooling systems

It should be noted that maintaining the optimal temperature regime in the car engine requires protection not only from exorbitant overheating, but also from the freezing. The supercooling of the unit can cause condensation of the fuel-air mixture caused by the contact of the fuel with the cool surface of the cylinders.

Fake in Carter power plant, it leads to a discharge lubricantWhat is reflected by the loss of most of its useful characteristics.

Mixing fuel with oil causes an annoying drop of motor power. Functionally important engine parts are faster wear. Also, the negative point is to thicken the oil in a supercooled unit. The deterioration of the timely feed of the lubricant to the cylinders leads to an exorbitant fuel squabble, the functional ability of the engine is significantly reduced.

In addition to performing the main function, the cooling systems are additionally provided:

lowering the temperature of the exhaust gases in the recycling system;
ventilation and air conditioning in the car. They are also responsible for heating;
timely cooling of motor oil;
maintaining the optimal temperature balance in turbocharging units;
cooling the working fluid filling the box-machine.

Appointment and principle of operation of the air cooling system

It has been established that the engineering engine causes a non-promotional fuel consumption, a large amount is also spent machine oil. Essential for the normal functioning of the car, the parts quickly fail due to the ambulance. In addition, the violation of the temperature regime can lead to the unreasonable loss of the motor required power.

Using the air cooling system in the engine, the optimum temperature is supported. Also, its purpose is to control air heating in the car. She follows the timely cooling lubricants, Reduces the temperature of the working fluid that fills the box-machine, and sometimes supports the optimal mode in the throttle node and the receiving manifold.

The principle of operation of the system consists in mastering the heat in the flow of air from excessively heated parts of the operating engine. In this way, cylinders, block heads and oil radiator are cooled.

The air flow to the engine is injected into force by aluminum fan blades protected by a special grid from an unwanted hitting random items capable of damaging the unit. The deflectors evenly distribute the air entering the cooling edges between all the parts of the functioning motor.

Fan design

It should be noted that forced air cooling is impossible without special Device. The fan that is the necessary link of the system under consideration consists of the following details:

guide diffuser, equipped around the circle stationary, radially located vocabulary blades that affect the uniform distribution of the air flow;
the rotor having eight special blades placed on the radius;
aluminum blades that injected air flow in the required direction;
casing preventing heat from entering the external space;
a protective grid that protects the mechanism from the accidental penetration of foreign objects inside the device.

The blades of the diffuser vary the direction of the air flow, and it rushes towards the opposite rotation of the rotor. This contributes to an increase in atmospheric pressure, causing best cooling Engine.

Advantages and disadvantages of the engine cooling system by air

Separately, it should be noted that sometimes to ensure the normal temperature regime is quite a natural circulation of atmospheric streams. The outer surface of the cylinders of mopeds, motorcycles, piston and other protozoa engines is equipped with special ribs that contribute to the return of heat into the external environment.

Complex design car motor Requires forced cooling. Airflow must be given a specific direction. Fans are used for this purpose.

Air-cooled engines possess the following advantages:

extreme simplicity of construction, a significantly simplifying repair process or replacement of parts that came to unsuitable;
relatively low weight;
solid reliability;
acceptable cost;
good characteristics of cold start motor.

However, before choosing a car with an air cooling engine, you should read with the disadvantages of the systems under consideration. They are characterized by:

exorbitant noise that is created by the operating fan;
an increase in engine size due to the need for additional space to place a blowing device;
uneven direction of air flow, which determines the possibility of local overheating;
excessive sensitivity to the quality of fuel, lubricants, as well as increased demands for the state of spare parts.

Nevertheless, air cooling has acquired its niche in the automotive industry. Such engines equip the trucks, agricultural equipment and diesel engine cars.

Common myths about "air-term", truth or fiction

Unfortunately, the disadvantages of "Zaporozhets" finally undermined the confidence of domestic motorists to the air cooling air system. She was accused of severe heating, insufficient power and a rapid way out of order. While the German "Beetle", equipped with a similar system, enjoys considerable popularity in consumers, glad the manufacturer with constant in increased demand.

Equiming the characteristics of the German car, exploring some fairly common legends, pursuing air cooled engines.

Approval 1. "Investership" loses liquid system due to strong heating

By no means an immutable truth. In fact, temperature features, on the contrary, can be considered the advantage of the engine cooled by air flow. Of course, the reduced thermal conductivity does not allow the air to select heat with sufficient velocity provided by water or antifreeze.

However, the difference between the temperatures on the surface of the cylinders and in the external environment is much more difference between the walls and the liquid moving inside the system. Therefore, weather conditions have a lesser extent affect the thermal regime of "air". The possibility of overheating of the motor with liquid cooling in the heat is much higher.

Approval 2. Large dimensions

Also very controversial. When comparing the sizes of two engines having equal diameters of cylinders and the same piston stroke, but equipped with different cooling systems, the advantage is often on the side of the "air".

Despite the rather impressive type of fan with a deflector and sufficiently bulky housings surrounding cylinders with heads, its parameters are somewhat more compact than that of the liquid aggregate.

In addition, "Waterka" occupies a much larger space due to additional equipmentdriven by engine. On the body there is a very bulky radiator equipped with a fan. Also a large number of all kinds of hoses do not add compactness.

Approval 3. Air systems lose fluid in reliability

It does not correspond to reality. Statistical studies argue that in one of five cases, the engine failure is watered on liquid cooling. The reason is the refusal details like the thermostat, radiator, pump, etc.

The simplicity of design ensures the reliability of the fan with a deflector explained by the low probability of breakage. In addition, an attractive moment indicative in favor of "air-term" is considered to reduce system maintenance costs.

Approval 4. Air cooling too loud

Unfortunately, is true. Constructive features The air system does not provide effective sound-absorbing devices with which liquid engine. In addition, the edges of the cylinders and the heads of "air" sometimes, on the contrary, enhance the noise produced by the functioning motor.

Designers have provided sound insulation of the liquid system, carried out by double the walls of the cooling shirt, inside which the antifreeze or water circulates. Therefore, in this position "Investership" really turned out to be losing.

Approval 5. Air engines are faster wear out

It is correct in relation to obsolete systems. The fan just pulled the air flows on the ribs of cylinders, without providing sufficient uniformity of blowing. Modern engines Characterized by rational heat distribution.

In addition, the higher temperature on the walls of the cylinders of "air" contributes to the reduction of the losses caused by the friction of the rings about the cylinders due to the best dilution of lubricants. This explains the smaller wear of the details. The oil is less undergoing oxidation, which slows down its aging, allowing you to save on a frequent replacement.

Approval 6. Insufficient power

Not quite right. The reason for this charge is the deterioration of the weight filling of the cylinders of the working fluid, which causes a short-filling drop in the engine power. This is due to the increase in the temperature of the cylinders and the heads with an increase in the load, which leads to the unwanted heating of the air inside the system.

However, with more revolutions, the difference in the filling factor air engines And liquid motors becomes less than 3.5%, established studies, practically rushing to zero. Therefore, it is possible to fight with a loss of recoil, increasing momentum.

Conclusion

So, the study has proven that the air cooling is not worse than liquid, and in some parameters, it exceeds it. Is it time to make it time to think about the resumption of car release with air systems? The demand of consumers will grow, despite the sad experience of the ill-fated "Cossacks".

radiator
expansion tank
cooling fluid pump
fan
thermostat
feeding highways

Engine cooling system give a chance quick warm warming engine and protects it from overheating, supporting optimum temperature. The radiator is connected by a tube with an expansion tank. The neck of the radiator closes the plug equipped with a safety valve dropping over the heated fluid from the radiator into the expansion tank, as well as the intake valve, which makes it possible to return the fluid into the radiator in the case of a decrease in the engine temperature.

At the traffic jam in the "closed" position, the protrusions should lay down to the tank. The fluid level is checked on the expansion tank. In the case of a decrease in the level of fluid below the "Low" tag, it is necessary to add it so much that the level rose to the "FULL" mark.

The coolant pump mounted in the front of the engine housing is driven by a gear distribution mechanism with a gear distribution.

Fig. Composite parts of the cooling system in the car (radiator, expansion tank, fan): 1 - radiator, 2 - radiator cork, 3,4,5 - fastening elements, 6 - fan casing, 7 - fan impeller, 8 - fan motor, 9 - Expansion tank, 10 - tube connecting the radiator with an expansion tank

Fig. Composite parts of the cooling system (liquid supply line): 1 - thermostat cover, 2 - cover of the lid, 3 - thermostat, 4 - submissive radiator hose, 5 - removal radiator hose, 6 - engine lining hose, 7 - Engine receiving nozzle, 8 - Gasket, 9 is a heating radiator heating hose, 10 - removing heating device driving radiator.

The main elements of the liquid cooling system and their purpose

In liquid cooling systems piston engines circulates on a closed contour, and heat dissipates in environment Using air-free radiator.

The main parts of the liquid cooling system:

Cooling shirt (1) is a cavity that envelope parts of the engine requiring cooling. Circulating the cooling shirt The liquid takes heat from them and transfers it to the radiator.
Cooling fluid pump, or pump (5) - ensures the circulation of fluid along the cooling contour. In some engines, such as mini-tractors, the thermo-and-diaphic cooling system can be used - that is, a system with a natural circulation of the coolant in which this pump is absent. It can be driven either through belt transmission from the engine shaft, or from a separate electric motor.
Thermostat (2) - Designed to maintain engine operating temperature. The thermostat redirects the coolant in a small circle - bypassing the radiator if the temperature did not reach the worker.
Radiator Cooling systems (3) usually has a plate-in structure, which is blown out outside the air flow. Usually, aluminum is used for the manufacture of the radiator, but other materials well conductive heat can also be applied. For example, copper is not rarely used for the manufacture of oil radiators.
Fan (4) is necessary for the injection of additional air to blow the radiator, including during stopping and when moving at low speed. In the old car models, the fan moved from the engine shaft using the belt transmission, but in modern cars, with the exception of large trucks, it works from the electric motor.
Expansion tank Contains the reserve of coolant. With the atmosphere, the expansion tank is reported through a valve supporting the excessive pressure of the coolant during operation, which allows the engine to operate at a larger temperature, not allowing the boiling of coolant. In old models of cars often expansion tanks There were no coolant stock in the radiator's top tank. With the propagation of antifreeze based on ethylene glycol, the use of an expansion tank has become mandatory, because When heated special fluid It has an extension property.

Figure shows liquid system Cooling 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 shirts of the cylinder heads pre-passes through the water shirt of the inlet tube, wash the walls and heats the mixture from the carburetor inner canals Pipes. 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. Thereby cold air It passes through the core of the radiator, taking it from him 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 presenter and with crankshaft Using the 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. By turning the lever of the Hydromefta switch, you can specify 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 ( working fluid Released from 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 oil canal in the housing of the switch and the working fluid - motor oil - Enters the working cavity of the hydromeflip 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 ( carburetor 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 supports the normal temperature mode 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 placed inside it air valve 6. Steam valve under the action of spring 2 tightly closes the neck of the radiator. If the water temperature 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 temperature of the coolant serve signal lamp and remote thermometer. 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.