Schemes of engine cooling systems, the principle of operation

The schemes of engine cooling systems are almost identical on all machines. On modern cars the hybrid system is applied. Yes, it is this, because not only liquid but also air participates in cooling. They blow the radiator cells. Due to this, cooling is much more efficient. It's no secret that at low speed the circulation of the liquid does not save - it is necessary to additionally install a fan on the radiator.

Radiator fan

Let's talk about domestic cars, for example about "Lada". To ensure better heat transfer, the engine cooling system ("Kalina"), which has a standard configuration, contains a fan. Its main function is to blow out the cells of the radiator with a stream of air when the liquid reaches a critical temperature value. The operation is controlled by a sensor. On domestic cars, it is installed in the lower part of the radiator. In other words, there is a liquid that gave heat to the atmosphere. And it should have a temperature of 85-90 degrees at this point of the contour. If this value is exceeded, additional cooling must be carried out, otherwise the boil will come into the engine jacket. Consequently, the motor will operate at critical temperatures.

Radiator cooling

It serves to release heat to the atmosphere. The liquid passes through the honeycombs, which have narrow channels. All these cells are connected by thin plates, which improve the heat output. When moving at high speed, air passes between the cells and helps to achieve a quick result. This element contains any scheme of the engine cooling system. Volkswagen, for example, is also no exception.

Above was considered a fan, which is mounted on the radiator. It blows air when the critical temperature is reached. To improve the efficiency of the element, it is necessary to monitor the cleanliness of the radiator. Its honeycombs are clogged with garbage, heat exchange is deteriorating. Air passes badly through the cells, heat is not produced. The result is that the temperature of the engine rises, its performance is disturbed.

Thermostat system

It is nothing but a valve. It reacts to the temperature change in the cooling system circuit. More about them will be described below. The scheme of the UAZ engine cooling system is based on the use of a quality thermostat, which is made of a bimetallic plate. Under the influence of temperature, this plate is deformed. It can be compared with an automatic switch used in electricity supply of houses and enterprises. The only difference is that the control is not controlled by the contacts of the circuit-breaker, but by the valve that supplies hot liquid to the circuits. In the design there is also a return spring. When the bimetallic plate cools , it returns to its original position. And the spring helps to return to it.

Sensors used in cooling

Only two sensors are involved. One is installed on the radiator, and the other is in the engine block jacket. Let's go back to the domestic cars and remember the "Volga". The scheme of the cooling system (405) of the engine also has two sensors. And the one on the radiator has a simpler design. It also has a bimetallic element, which deforms when the temperature rises. This sensor switches on the electric fan.

On cars of the classic VAZ series, a direct fan drive was previously used. The impeller was mounted directly on the pump axis. Rotation of the fan was carried out constantly, no matter what the temperature in the system. The second sensor, installed in the engine jacket, serves for one purpose - signal transmission to the temperature indicator in the passenger compartment.

Liquid Pump

Let's go back to the Volga. The engine cooling system (406), the circuit of which contains a circulating liquid pump, can not simply function without it. If you do not give the fluid movement, then it can not move along the contours. Consequently, stagnation will appear, the antifreeze will start to boil, and the motor can jam.

The design of the liquid pump is very simple - an aluminum casing, a rotor, a drive pulley on one side and a plastic impeller on the other. The installation takes place 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 model 2108. In the second case, the drive is carried out from the crankshaft pulley .

Contour of the stove

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

In all cars, the heater radiator is mounted under the instrument panel. First, the fan assembly is installed, then on it - the radiator, and on top fit the air ducts. They are necessary for distribution of hot air in the salon. In new cars, distribution control is performed using microprocessor systems and stepper motors. They open or close the dampers depending on the temperature in the cabin.

Expansion tank

Everyone knows that any liquid when heated expands - increases in volume. Therefore it is necessary that she go somewhere. But on the other hand, when the liquid cools, its volume decreases, therefore, it is necessary to add it again to the system. It is impossible to do this manually, but with the help of an expansion tank this procedure can be automated.

In most modern cars, schemes of engine cooling systems are hermetic. For these purposes, the presence of a plug on the expansion tank with two valves: one for the inlet, the second for the outlet. This makes it possible to provide in the system a pressure close to one atmosphere. With a decrease in its index, air is sucked in, and when it is increased, it is discharged.

Chimneys of cooling systems

To ensure the circulation of fluid circuits of engine cooling systems contain rubber nipples. With their help, fluid is transferred between the nodes. A branch pipe is a rubber tube. Inside, it has reinforcement, which increases the strength of the product. The nozzles are of different length and shape. These parameters depend on the model of the car.

Fastening of branch pipes is made with the help of metal clamps of worm type. To ensure maximum tightness, silicone sealants can be used. It is reasonable to use them when there are small defects in the connection points of the nozzles to the cooling system. Thanks to the sealant, all irregularities are filled. When operating the vehicle, it is necessary to monitor the condition of the nozzles carefully. Do not allow the appearance of cracks, otherwise there will be a leakage of fluid and a breach of the integrity of the system.

conclusions

After a thorough analysis, you can see that the scheme of the engine cooling system, despite the configuration, is the same on all cars. For effective operation of the system, it is necessary to monitor the state of all its elements. Not only does the failure of the thermostat, but even the failure of the valves in the expansion tank cap, cause the coolant temperature to rise. Therefore, you need to make timely maintenance of the system, so that at the wrong time it does not fail. Otherwise, the engine may be malfunctioning. Excessive overheating of the cylinder block can lead to the appearance of cracks, as well as wedging of the piston group.