Ford Focus>> Management of the power unit and the fulfilled gases>> Nozzles spray diesel fuel

Fig. 210. Double process of injection: 1, 2 — a spring; 3 — size of lifting of a needle at compression of the first spring; 4 — total size of lifting of a needle; 5 — size of lifting of a needle at compression of the second spring; And — the nozzle is closed; In — predaritelny injection; With — the main injection



Nozzles spray fuel under a high pressure in the combustion chamber. For reduction of noise of combustion and vzryvoobrazny growth of pressure in the cylinder of a nozzle work with two springs having various characteristics. The first spring has such characteristic at which the needle of a nozzle rises at pressure of 105 000 kPas, thus in the chamber of combustion a small amount of fuel which (fig. 210) ignites moves .
The first portion of injection provides soft increase of pressure in the combustion chamber, it works to a certain extent as "match" for the main injection, from the beginning of pressure of 110 000 kPas. Thus the nozzle needle completely rises from the saddle and injects the main amount of fuel through five openings into the combustion chamber. The air turbulences accruing at burning, grasp fresh parts of fuel and form homogeneous and easily combustible working mix. The strong springs operating on a needle of a nozzle, prevent pressure emission from the combustion chamber in a power supply system. Time between the beginning of injection and ignition of fuel makes 0,002 pages.