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Design Features
The structure of the power supply system includes elements of the following systems: - The fuel supply includes a fuel tank, elektrobenzonasos, fuel filter, fuel pressure regulator and fuel rail lines with the nozzles; - Air supply, which includes air filter, throttle assembly, the regulator of idling; - EVAP, consisting of a canister, the canister purge valve and pipework.
NOTE Fuel vapor recovery system is described in a separate subsection (cm. "EVAP system"), as it serves only to fulfill the environmental requirements to reduce toxicity. |
Functionality of the fuel system - providing a supply of the required quantity of fuel into the engine at all operating states. The engine is equipped with an electronic control system with fuel injection. The injection system features mixing and dispensing feed fuel mixture in the engine cylinders are divided: air is air supply system consisting of the throttle assembly and idle speed regulator and necessary in every moment of the engine fuel injection nozzle into the inlet pipe. This method of governance makes it possible to ensure the optimum composition of the fuel mixture at any given moment of the engine to provide maximum power at the lowest possible fuel consumption and low emissions. Controls the fuel injection system (and ignition system too) electronic control unit continuously monitored using appropriate sensors engine load, vehicle speed, the thermal state of the motor, optimal combustion process in the engine cylinders. The system prevents the fuel vapor recovery system out of food in an atmosphere of fuel vapors, adversely affecting the ecology of the environment. The system used the method of vapor absorption carbon adsorber. It is mounted on the base stand and the right rear pipes connected to the fuel tank and the intake pipe. On the bracket mounted on the inlet pipe, located canister purge solenoid valve, which signals the engine control unit switches the operation modes of the system. Fuel vapors from the fuel tank through conduit continuously discharged and accumulated in the adsorber filled with activated charcoal (adsorbent). When the engine is regenerated (recovery) adsorbent canister purge of fresh air coming into the system by the action of vacuum transferred through a pipeline from the inlet tube into the cavity of the canister when the valve opens. The magnitude of valve opening, and hence the intensity of the canister purge depend on the angle of rotation of the throttle and defined vacuum that occurs within the cavity inlet pipe running engine. Fuel vapor from the adsorber via line enters the intake pipe of the engine and are burned in the cylinders. Malfunction of the fuel vapor recovery system entail instability idling, stop the engine, increased exhaust emissions and the deterioration of the driving characteristics.
| Fig. 5.21. Scheme loop fuel ratio: 1 - a sensor of oxygen concentration in the exhaust gases (a lambda probe); 2 - the exhaust manifold; 3 - engine; 4 - nozzle; 5 - the engine control unit; 6 - catalytic converter exhaust |
The main sensor for optimum combustion process is a gauge of concentration of oxygen in the exhaust gas (lambda probe). It is installed in the exhaust manifold of the engine and with an electronic unit injector and a correction circuit forms the air-fuel mixture supplied to the engine (Fig. 5.21). The sensor signals the engine control unit determines the amount of unburned oxygen in the exhaust gases and thus is optimally air-fuel mixture fed into the engine cylinders at each moment. A deviation from an optimal composition 1:14 (respectively fuel and air), providing the most efficient operation of the catalyst exhaust gas control unit via the nozzles changes the composition of the mixture. As a result, the control loop-fuel ratio is closed.  Fuel tank welded, stamped, installed under the floor of the body at its rear portion and is fixed by four bolts. In order not to fuel vapors into the atmosphere, the tank is piped to the adsorber. In flanged opening at the top of the tank an electric fuel pump. Fuel is supplied from the pump to the fuel filter installed in the engine compartment on the bulkhead, and thence supplied to the fuel rail of the engine, mounted on the inlet pipe. From the fuel rail fuel injection nozzle into the intake pipe. The fuel supply system is a tube, interconnecting the various elements of the system.
WARNINGS It does not replace steel piping hoses, tubes of copper or aluminum, since only steel pipes satisfy operation at elevated pressure and vibration. Hoses of power produced by a special technology of oil and gasoline resistant materials. The use of hoses which differ in design from those recommended may lead to a denial of food, and in some cases fire. The pipe connections with the power system elements are used round the sealing ring. Use of seals of different construction is prohibited |
Fuel pump module includes an electric pump and fuel gauge sender. The module of the fuel pump supplies fuel in the fuel tank is installed, which reduces the possibility of vapor lock, since the fuel is supplied under pressure and not under the influence of vacuum. Fuel pump submersible rotary type electric. Pump folding design can not be repaired, in case of failure it must be replaced. Fuel fine filter - full flow, is attached to a bracket mounted on the bulkhead in the engine compartment. Filter molded, it consists of a steel body with a paper filter element. Fuel rail 2 (Fig. 5.22) is a hollow molded piece with holes for the nozzles 3, with a flange for mounting the fuel pressure regulator and with fitting for connection of high pressure fuel. The nozzles are sealed in the holes in the sockets of the ramp and the inlet pipe with rubber rings 4 and secured with spring clamps 1. On the flange of the ramp is attached with two screws 5 the fuel pressure regulator, which is connected to the fuel drain pipe. The ramp with nozzles and regulator assembly shank inserted into the holes nozzles inlet tube and secured with two screws.
| Fig. 5.22. Fuel rail: 1 - lock the nozzle; 2 - ramp; 3 - nozzle; 4 - a sealing ring of nozzles; 5 - fuel pressure regulator |
Nozzles (Fig. 5.23) are attached to the rail from which fuel is supplied to them, and their nozzles into holes of the inlet tube. The openings of the inlet tube and the ramp nozzles are sealed with rubber O-rings 1 and 3. The nozzle is designed for the metered injection of fuel into the engine cylinder, and is a precision electromechanical valve. Fuel is supplied under pressure from the rail through channels within the nozzle body to the gate valve. A spring biases the needle check valve opening to the cone plate nebulizer, keeping the valve in the closed position. Voltage supplied from the engine control unit via plug pins 2 to the injector solenoid coil, it creates a magnetic field, retracting the needle core together with the check valve inside the electromagnet. Conical annular opening in the plate atomizer is opened, and fuel is injected through the diffuser of the dispenser into the intake port of the cylinder head and further into the engine cylinder. After receipt of the termination of an electrical impulse spring returns the core and the needle shut-off valve to its original state - the valve locks. The amount of fuel injected by the nozzle depends on the duration of the electric pulse.
| Fig. 5.23. Injector fuel injection system: 1 - lower gasket; 2 - plug the winding of the electromagnet; 3 - upper sealing ring |
The fuel pressure regulator installed on the fuel rail, maintains a constant fuel pressure in the central channel of the ramp in all modes of operation. Regulation of the fuel pressure supplied to the injector, based on the principle of monitoring the value of the differential pressure in the rail and intake manifold, which in all circumstances should be not less than 300 kPa (3.0 kgf / cm 2). Submission of the electric fuel pump more than is necessary to ensure the efficiency of the system. Therefore, when the engine via a pressure regulator of the fuel is continuously discharged through the return line to the fuel tank. Depending on the vacuum in the intake manifold pressure regulator reduces or increases the draining of excess fuel by maintaining a constant pressure in the rail. The pressure regulator is a closed chamber, separated by a diaphragm in the vacuum chamber and fuel. The vacuum chamber communicates through a vacuum hose from the intake pipe of the engine, the fuel - through a channel in the regulator body with a cavity fuel rail. During engine operation by the spring regulator valve is closed if the pressure drop in the intake pipe and the fuel rail is not more than 0.3 MPa. Backleak not - the pressure in the fuel begins to rise. At a pressure drop of more than 300 kPa (3.0 kgf / cm 2), the diaphragm flexes and regulator between the valve seat and a gap through which the other channel controller coupled to the drain pipe is drained excess fuel - pressure is reduced. By increasing the load on the motor running at high throttle, fuel consumption increases and the fuel rail pressure drops. Simultaneously, underpressure decreases in the intake pipe. The spring presses the pressure regulator valve to the seat, drain the fuel into the fuel tank is stopped - the pressure increases. These processes are repeated continuously, resulting in the fuel rail constant pressure.  The air filter is installed in the right front of the engine compartment on the mudguard of the engine. Lower the filter tube is inserted into the duct inlet silencer, installed under the right front fender. The filter is connected to air supply corrugated rubber sleeve with throttle assembly. The filter element of the air filter paper, flat with a large filter surface area. A throttle assembly is an easily controlled device, and serves to change the number of primary air supplied to the intake system of the engine. It is installed at the inlet flange of the inlet tube. On the inlet throttle knot wearing a molded rubber sleeve fixed yoke and throttle device connects to the air filter. In the case of throttle knot a hole for supplying additional air to the regulator of idling.
| Fig. 5.24. Throttle knot: 1 - throttle position sensor; 2 - a regulator of idling; 3 - throttle; 4 - sector of the throttle; 5 - the throttle body assembly |
The housing 5 (Fig. 5.24) is installed on the swivel axis of the flap 3. At one end of the axis of the sensor 1, the throttle position the engine management system, on the other - Sector 4, joined the accelerator cable. The main body 5 is fixed knob 2 idling, metering the flow of air at the closed throttle. The air filter unit is not seasonal adjustment, so the throttle device is equipped with a heating system which prevents the icing throttle during the cold season, and connected to the engine cooling system hoses. In the operation of the throttle device requires no maintenance and adjustment should only be the state of the rubber seals to prevent air leaks. The regulator maintains the desired idle speed of the engine idle when the throttle is fully closed during its start-up, warming and load changes when the auxiliary equipment. The controller adjusts the amount of secondary air supplied to the intake system in addition to the throttle valve, and an electromechanical valve is attached with two screws to the flange of the throttle body assembly. Executed in the flange of the throttle device the valve seat and the channels form a system controller supplying additional air bypassing the throttle valve.
| Fig. 5.25. The regulator Idle: 1 - Valve; 2 - regulator body; 3 - stator winding; 4 - spindle; 5 - pin terminal of the stator winding; 6 - ball bearing; 7 - the case of the stator windings; 8 - rotor; 9 - Spring |
The engine control unit, the processed signals from the sensors, determines the need for opening the valve 1 (Fig. 5.25), and transmits the control pulses to the pin terminal 5 of the stator winding 3 controller. Each driving pulse rotor 8 is rotated at a certain angle, by moving the spindle 4 the valve 1 relative to the seat. In the inlet pipe through the channels in the throttle node receives additional air. Defining the vacuum in the intake pipe of the engine control unit aims to maintain it at a given level, periodically opening and closing the valve regulator of idling. This makes it possible to provide a constant flow quantity of supplementary air to maintain a constant idle speed. By varying the valve opening and closing control, the control unit compensates for a significant increase or decrease the amount of air caused by suction through its unsealed inlet system or alternatively, the air filter clogging. Inclusion of additional units causes an increase in the load of the engine, accompanied by a decrease in idle speed and change the vacuum in the intake pipe, which is also compensated by the control unit using the controller.
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