FUEL INJECTION CONTROL DEVICE AND METHOD OF CONTROLLING FUEL INJECTION FOR AN INTERNAL COMBUSTION ENGINE

摘要

An outer needle valve (42) and an inner needle valve (43) face on back sides thereof an outer control chamber (R2) and an inner control chamber (R3), which are independent of each other, respectively. An outer fuel outflow passage (C4) and an inner fuel outflow passage (C5) for causing fuel to flow out from the outer control chamber (R2) and the inner control chamber (R3) respectively meet at a meeting portion (Y). A control valve (45) for rendering in communication/shutting off a fuel discharge passage (C6) for connecting the meeting portion (Y) to a fuel tank (T) is interposed in the fuel discharge passage (C6). An automatic valve (44) as an open/close valve for shutting off the outer fuel outflow passage (C4) when a rail pressure (Pcr) is equal to or lower than a predetermined value and rendering in communication the outer fuel outflow passage (C4) when the rail pressure (Pcr) is higher than the predetermined value is interposed in the outer fuel outflow passage (C4).