| 摘要 |
Disclosed a common-rail fuel-injection system employing an auxiliary injection such as a pilot injection system, in which when a desired amount(Qt) of fuel to be injected in the auxiliary injection is less than a set value, the feedback control ceases to keep the combustion against becoming unstable. When a desired amount(Qt) of fuel to be injected in the auxiliary injection is proved on comparison at step 15 to be less than a minimum amount(Ql) of fuel injected, which is the lower limit detectable according to both of the common-rail pressure and a pressure drop in the common-rail pressure owing to the fuel injection,the minimum amount(Ql) of fuel injected serves on step 18 as a corrected, desired minor amount(Qc) of fuel to be injected in the auxiliary injection. Thus, the fuel injection is achieved in accordance with the corrected, desired amount(Qc) of fuel to be injected in the auxiliary injection, thereby keeping the feedback control at the auxiliary injection from becoming unstable. As an alternative, the minimum amount(Ql) of fuel injected may be replaced with a set value for an amount of fuel injected, which is defined on the basis of the minimum amount(Ql) of fuel injected. <IMAGE> |
