5.14.1. Features of a design
The structure of a power supply system includes elements of the following systems:
– system of supply of the fuel, including a fuel tank, the fuel pump with the built-in regulator of pressure of fuel, pipelines, a fuel stage with nozzles, and also the fuel filter;
– system of supply of the air, including the air filter airbringing a sleeve, throttle knot, an idling regulator;
– catching system паров the fuels, including an adsorber, the valve of a purge of an adsorber, a separator паров fuels and connecting pipelines.
Functional purpose of system of supply of fuel — ensuring giving of necessary amount of fuel in the engine on all operating modes. The engine is equipped with an electronic control system with the distributed injection of fuel. In system of the distributed injection of fuel of function of a smeseobrazovaniye and dispensing of giving of a toplivovozdushny mix in cylinders of the engine are divided: nozzles carry out the dosed-out injection of fuel in the inlet pipeline, and necessary during every moment of operation of the engine the amount of air moves the system consisting of throttle knot and a regulator of idling. Such way of management gives the chance to provide optimum composition of gas mixture during each concrete moment of operation of the engine that allows to receive the maximum capacity at minimum possible fuel consumption and low toxicity of the fulfilled gases. The electronic control unit the engine which is continuously supervising by means of the corresponding sensors loading of the engine, speed of movement of the car, a thermal condition of the engine, an optimality of process of combustion in engine cylinders operates system of injection of fuel and ignition system.
Feature of system of the phased injection of fuel is synchronism of operation of nozzles according to gazoraspredeleniye phases (the control unit the engine receives information from the phase sensor). The control unit includes nozzles consistently, instead of in pairs, as in systems of asynchronous injection. Each nozzle joins through 720 ° turn of a cranked shaft. However on modes of start-up and dynamic power setting the asynchronous method of supply of fuel without synchronization with rotation of a cranked shaft is used.
The main sensor for ensuring optimum process of combustion is the sensor of concentration of oxygen in the fulfilled gases (lambda probe). It is established in a reception pipe of system of production of the fulfilled gases and together with the control unit the engine and nozzles forms a contour of management of structure of the toplivovozdushny mix submitted to the engine (fig. 5.11). The control unit determines by the engine amount of not burned down oxygen by sensor signals in the fulfilled gases and respectively estimates an optimality of structure of the toplivovozdushny mix arriving in cylinders of the engine during every moment of time.
Fig. 5.11. Scheme of a contour of management of structure of a toplivovozdushny mix: 1–the sensor of concentration of oxygen in the fulfilled gases (lambda probe); 2–final collector; 3–engine; 4–nozzle; 5–control unit engine; 6–catalytic converter of the fulfilled gases
Having fixed a structure deviation from the optimum 1:14 (fuel/air), catalytic converter of the fulfilled gases providing the most effective work, the control unit by means of nozzles changes mix structure. as the sensor of concentration of oxygen is switched on in a chain of feedback of the control unit by the engine, the contour of management of structure of a toplivovozdushny mix is closed.
The fuel tank is made of plastic, established under a body floor and attached to a body floor by three arms.
The bulk pipe is made for a single whole with a fuel tank. In order that pairs of fuel did not get to the atmosphere, the tank is connected by the pipeline to an adsorber. In a flange opening in the top part of a tank the electric fuel pump with the fuel level sensor is established. From the pump fuel moves in the fuel filter established under a body floor in its back part on the right. Via the threefold union on an exit from the fuel filter fuel is distributed on two highways. On one highway it moves in the fuel stage fixed on the inlet pipeline. On the second highway superfluous fuel through the regulator of pressure established in the fuel module, comes back back to a tank.
Toplivoprovoda and hoses of a power supply system are made on special technology of maslobenzostoyky materials.
Application топливопроводов, differing on a design from recommended by manufacturer, can lead to power supply system refusal, and in certain cases even to a fire.
The module of the fuel pump includes the electric pump, a regulator of pressure of fuel...
... and sensor of the index of level of fuel.
The module of the fuel pump provides supply of fuel and is established in a fuel tank that reduces probability of formation of steam jams as fuel moves under pressure, instead of at the expense of depression. Greasing and cooling of details of the fuel pump Besides, improves.
The fuel pump pogruzhny, lopastny type, with the electric drive. The pump of not folding design, is not subject to repair, at failure it is necessary to replace it.
The regulator of pressure of fuel is established in the module of the fuel pump and intended for maintenance of constant pressure of fuel in a fuel stage. The regulator is connected in the beginning of the submitting highway (at once after the fuel filter) and represents perepuskny the valve with a spring which effort is strictly calibrated.
The fuel filter of thin cleaning — polnopotochny, is fixed in an arm under a body floor in its back part on the right. The filter not folding, consists of the steel case and a paper filtering element.
The fuel stage
2 (fig. 5.12)
represents a hollow detail with openings for nozzles 3 with the union for accession топливопровода a high pressure and fastening arms to the inlet pipeline. Nozzles are condensed in openings of a stage and in nests of the inlet pipeline with rubber rings 4 and fixed by spring clamps 1. The stage assembled with nozzles is inserted by shafts of nozzles into openings of the inlet pipeline and fixed by two bolts.
|Fig. 5.12. Fuel stage: 1–nozzle clamp; 2–stage; 3–nozzle; 4–sealing ring of a nozzle
Nozzles (fig. 5.13)
are attached to a stage from which to them fuel moves, and the sprays enter into openings of the inlet pipeline. In openings of a stage and the inlet pipeline of a nozzle are condensed with rings 1 and 3. The nozzle is intended for the dosed-out injection of fuel in the cylinder of the engine and represents the high-precision electromechanical valve. Fuel under pressure arrives from a stage on channels in the nozzle case to the locking valve.
|Fig. 5.13. Nozzle of system of injection of fuel: 1–top sealing ring; 2–shtekerny conclusions of a winding of an electromagnet; 3–bottom sealing ring
The spring draws in a needle of the locking valve to a konusny opening of a plate of a spray, holding the valve in a closed position. The tension submitted from the control unit by the engine through shtekerny conclusions of 2 on a winding of an electromagnet of a nozzle, creates in it the magnetic field involving the core together with a needle of the locking valve in an electromagnet. Konusnoye a ring opening in a plate of a spray opens, and fuel is injected through a diffuzor of the case of a spray into the inlet channel of a head of the block of cylinders and further in the engine cylinder. After the termination of receipt of an electric impulse the spring returns the core and a needle of the locking valve in an initial condition — the valve is locked. The amount of the fuel injected by a nozzle, depends on duration of an electric impulse.
The air filter is established in the right forward part of a motor compartment on an engine mudguard.
The filter is connected by the rubber goffered airbringing sleeve to throttle knot.
Filtering element of the air filter paper, flat, with the big area of a filtering surface.
The throttle knot represents regulating device and serves for change of amount of the main air submitted to inlet system of the engine. It is established on an entrance flange of the inlet pipeline. The formed rubber sleeve fixed by a collar and connecting throttle knot to the air filter is put on an entrance branch pipe of throttle knot.
|Fig. 5.14. Throttle knot: 1–case of throttle knot; 2–idling regulator; 3–sensor of provision of a butterfly valve; 4–butterfly valve; 5–sector of a drive of a butterfly valve
In the case 1 (fig. 5.14)
of throttle knot the opening for a supply of additional air to an idling regulator is executed.
In the case 1 the butterfly valve turning on an axis 4 is established. On one end of an axis the sensor of 3 provisions of a butterfly valve of a control system by the engine, on other — sector 5 to which the cable of a drive of a butterfly valve is attached is established. On the case 1 the regulator of the idling 2 which is dosing out a stream of air at the closed butterfly valve is fixed.
In use the throttle knot does not demand service and adjustment, watch only a condition of rubber consolidations to avoid подсоса some air.
The regulator of idling supports the set frequency of rotation of a cranked shaft of the engine at completely closed butterfly valve during its start-up, warming up and at loading change during auxiliaries inclusion.
The regulator changes amount of the additional air submitted to inlet system passing a butterfly valve, and represents the step-by-step electric motor attached by two screws to a flange of the case of throttle knot.
The control unit the engine, having processed entering signals from sensors, defines necessary frequency of rotation of a cranked shaft of the engine and respectively position of the valve of a regulator. Changing position of the valve of a regulator, the control unit changes size of section of the bypass channel in throttle knot. The control unit compensates these significant increase or reduction of amount of the submitted air, caused its podsosy through not tight inlet system, or, on the contrary, a contamination of the air filter.
Turning on of additional units causes increase in loading at the engine, being accompanied decrease in frequency of rotation of idling and change of depression in an inlet pipe that also is compensated by the control unit by means of an idling regulator.