Injection device for direct injection diesel engines using alcohol and diesel fuel

摘要

The injection device has a nozzle body (10) wherein the liquid-controlled needle valves (17; 18) are opened by the diesel fuel supplied by an injection pump via the annular line (12) and the pressure channels (13; 14) when the opening pressure po, which is set at the pressure springs (19; 20) by way of the pressure adjusting discs (21; 22), is reached. In this connection the two needle valves (17; 18) can be opened and closed at different times within certain limits so that at a relatively low opening pressure po for the needle valve (17) relative to the needle valve (18) the diesel fuel issuing through the spray aperture (24) into the combustion chamber (25) serves during the entire injection period as ignition jet for the alcohol fuel issuing from one or more spray apertures (29). The alcohol fuel, which is supplied continuously by a gear pump, flows from the pressure channel (26) to the collecting chamber (27) from where, interrupted by the liquid-controlled needle valve (18), it is injected intermittently via the blind hole (28) and the spray aperture(s) (29) into the combustion chamber (25). Due to the intake of air in the narrowest cross section of the spray apertures (24; 29), diesel and alcohol fuel arrive at the combustion chamber (15) already as two-phase mixture.