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>> Systems of injection of fuel
>> Features of system of injection of 6-cylinder engines
On 6-cylinder engines the system of injection with preliminary preparation of gas mixture operated from the electronic module (ECM module) is installed. A basic element of system is the dosing system a part of which the case of a butterfly valve and a nozzle are (one or several). The amount of fuel is defined by time of an open condition of a nozzle and is set by the ECM module. The ECM module traces a condition of the engine and car and counts the optimum duration of the managing director of an impulse. The amount of injectable fuel changes also taking into account a special condition of the engine (start at usual and low temperatures, dispersal, braking by the engine, etc.).
The ECM module also provides control of the fulfilled gases due to maintenance of composition of benzino-air mix at the level of 14,7:1. At increase in duration of the operating nozzle impulse mix is enriched, and at reduction – is impoverished. Impulses move in 2 modes – synchronous and asynchronous.
In this mode the nozzle opens only at receipt of a reperny impulse from the ignition distributor. In systems their opening happens to two nozzles serially.
In this mode the nozzle opens with the period of 12,5 ms, or 6,25 ms, irrespective of a reperny impulse. The system of injection passes to the asynchronous mode in the following conditions:
– with very small duration of an impulse on a nozzle (less than 1,5 ms);
– when giving of the pumping-up impulses (these impulses give fuel to the soaking-up collector at start-up or before launch of the engine);
– at reenrichment of mix in the conditions of dispersal;
– when braking by the engine.
The block of injection of fuel with a butterfly valve (TBI block) consists of two main details – cases with the gate regulating an air stream and the fuel block with the built-in regulator of pressure and a nozzle. A part of the TBI block are also devices of automatic adjustment of turns of idling and definition of provision of a butterfly valve.
The nozzle represents the electromagnetic valve. Fuel comes to the lower part of a nozzle in which there is a filter of thin cleaning surrounding an inlet opening. Under the influence of the operating impulse the ball valve opens. Fuel is injected in the form of a cone-shaped stream from an opening in the case, directly over a butterfly valve. The rest of fuel gets to pressure regulator, and then goes to a tank.
The regulator of pressure represents the reducer blocked under the influence of effort from a diaphragm. On one side of a diaphragm fuel pressure, and on another – pressure in the air filter works. The regulator is intended for maintenance of constant pressure difference on a nozzle at various speeds of rotation of the engine and loadings.
Openings which are located before a butterfly valve or behind it are provided in the case of a butterfly valve. Depression in these openings moves on the recirculation valve, the sensor of absolute pressure in a collector, in system of a purge of vapors of gasoline.
The sensor of an angle of rotation of a butterfly valve represents the variable resistor which resistance is defined by position of the gate. The signal of provision of a butterfly valve is perceived by the ECM module as reperny. For automatic adjustment of idling the control air valve (IAC valve) mounted on the case of a butterfly valve is used as a signal from the sensor of an angle of rotation of a butterfly valve, and. This valve has conical shape and reports a cavity of the air filter with space behind a butterfly valve. The ECM module traces turns of idling and operates the IAC valve depending on engine loading, increasing or reducing an air stream.