5.1.6. Cooling system


Fig. 4.16. Scheme of connection of radiators of a heater with a faucet and electric pump: I \the scheme of connection with one heater (for GAZ-2705); II \the scheme of connection with two heaters (for GAZ-2705 of "KOMBI" and buses); 1 — a drain faucet of the cooling system of the engine; 2 — a heater faucet with the electric drive; 3 — the electric pump of system of heating; 4 — a radiator of an additional heater; 5 — a heater radiator; 6 — the taking-away heater radiator hose; 7 — a tee; 8 — a tee stopper; 9 — the thermostat case; 10 — the thermostat; 11 — the sensor of temperature of cooling liquid; 12 — a radiator; 13 — a drain stopper of a radiator; 14 — the fan; 15 — the pump of cooling liquid




The cooling system (fig. 4.16) — liquid, closed, with compulsory circulation, consists of a water shirt in the block and a head of cylinders of the engine, pump of cooling liquid, a radiator, a broad tank, the fan, thermostat, a stopper of a broad tank, a casing of the fan, a drain faucet and a stopper.
The scheme of the cooling system included a radiator of the 5th heater of a cabin, and for buses and GAZ-2705 of "Kombi", besides, a radiator 4 additional heaters and the electric pump 3.

Fig. 9.23. Measurement of provision of a gear wheel of the drive in the switched-off state




On the car the faucet 2 radiators of a heater with the electric drive is established. In one case the faucet connected through a mechanical reducer by the microelectric motor which is switched on by the handle 1 settles down (see fig. 9.23). The faucet has two provisions — is completely open or completely closed. Before turn of the handle on 90 ° to the right the crane is closed from a starting position, at further turn of the handle to the right against the stop — the crane is open. Use of a faucet — see the section "Heating and Ventilation of a Body".
In a drain branch of a radiator of a heater in its most top point the tee of 7 (fig. 4.16) is located. The tee is located in a cabin under the dashboard on the right side. In the provision of a stopper which is turned out on 2 — 3 turns 8 (see fig. 4.16) a tee there is a message of system of heating to the atmosphere that allows to exclude completely air traffic jams when filling the cooling system of the engine and system of heating with working liquid.
Maintenance of the correct temperature condition of the engine exerts decisive impact on wear of the engine and profitability of its work. Optimum temperature of cooling liquid (85 — 90 °C) is maintained by means of the thermostat operating automatically and a cover on facing of a radiator.
For control of temperature of cooling liquid there is an index of temperature which sensor is screwed in the thermostat branch pipe which is on a head of cylinders. Besides, on a guard of devices there is a signaling device which is lighting up red light at temperature increase of liquid it is above 105 °C. The sensor of a signaling device is in a back cover of a head of cylinders. At fire of a signaling device it is necessary to establish and remove the overheat cause immediately.

Fig. 4.17. Operation of the thermostat: And — the thermostat is closed; In — the thermostat is open




The thermostat (fig. 4.17) with a firm filler, two-valve, type CU-107-01, is located in an output branch pipe of a head of cylinders and connected by hoses to the pump of cooling liquid and a radiator.
The main valve of the thermostat begins to open at a temperature of cooling liquid of 78 — 82 °C. At a temperature of 94 °C it is already completely open. At the closed main valve liquid in the cooling system of the engine circulates, passing a radiator, via the open additional valve of the thermostat in a shirt of cooling of the engine. At completely open main valve the additional valve is closed and all liquid passes through a cooling radiator.
The heater of a body is connected to a radiator, and the thermostat does not disconnect it from the engine. Therefore at warming up of the engine it is not necessary to open the gate of airinflow and to turn on the heater electric motor.
The thermostat automatically maintains the necessary temperature of cooling liquid in the engine, disconnecting also including circulation of liquid through a radiator. In cold weather, especially at small loadings of the engine, almost all heat is taken away as a result of an obduv of the engine by cold air, and cooling liquid through a radiator does not circulate.
For maintenance of optimum temperature condition of the engine at negative temperatures of air it is necessary to close facing of a radiator a cover.
It is impossible to remove the thermostat at all. In cold season the engine without thermostat gets warm long and works at a low temperature of cooling liquid. As a result its wear accelerates, fuel consumption increases, there is a plentiful adjournment of resinous substances in the engine, and also normal air temperature in a car cabin is not provided.
In warm season in the absence of the thermostat the most part of cooling liquid will circulate on a small circle (through a shirt of cooling of the engine), passing a radiator. As a result it will lead to an engine overheat.

Fig. 4.18. Pump of cooling liquid: 1 — a clamp; 2 — an epiploon with a sealing washer; 3 — a control opening for an exit of cooling liquid




Fig. 4.19. Belts of the drive of auxiliary units: 1 — the drive of the water pump; 2 — a pulley of a tension roller; 3 — a fan drive pulley; 4 — a pulley of a bent shaft; 5 — a generator drive pulley




The pump of cooling liquid (fig. 4.18) — centrifugal type. The bearing of the pump is separated from cooling liquid by a samopodzhimny epiploon of a non-demountable design. The liquid which filtered through an epiploon does not get to the bearing, and follows outside through a control opening 3 which needs to be cleared periodically. The pump bearing refrains from movement by a clamp 1 which will be wrapped against the stop and закернен. The bearing is filled with lubricant at assembly, and in use addition of lubricant is not required. The pulley of the pump of cooling liquid is given to rotation together with a generator pulley one maple belt from a pulley of a bent shaft (fig. 4.19).
The fan — six-blade, plastic. It is brought into rotation from a bent shaft by a maple belt. The fan rotates in two bearings. Bearings are installed in the special arm fixed on a cover of distributive gear wheels by three hairpins.

Fig. 4.20. Radiator: 1 — a radiator; 2, 3, 4, 8, 13 and 14 — washers; 5 and 15 — nuts; 6 and 11 — arms; 7, 10 — the plug; 9 — a bolt; 12 — a pillow




Radiator (fig. 4.20) — tubular and tape, with side plastic tanks. Tanks are connected to a radiator skeleton through rubber sealing laying by snap of a basic plate on a flange of plastic tanks. On tanks and the top plate of a skeleton of a radiator there are arms for fastening of a radiator to a car body. On the right tank (on the car course) in the lower part there is a drain stopper for discharge of cooling liquid.
The broad tank — plastic, is connected by a hose to the branch pipe bringing the cooled liquid from a radiator to the engine and a tube — with a branch pipe of the thermostat and the left tank of a radiator. On a tank there is MIN tag — the lower admissible level of cooling liquid in a tank. The broad tank is closed by the carving stopper supporting elevated pressure in the cooling system.
The stopper of a broad tank hermetically closing the cooling system has two valves: the steam, opening with a pressure of 80 — 110 kPa (0,8 — 1,1 kgfs/cm2), and air, opening at depression 1,0 — 10 kPa (0,01 — 0,1 kgfs/cm2).