| 摘要 |
PURPOSE:To reduce noise and NOx by suppressing the initial injection rate and the pressure increase rate by carrying out the pilot injection by auxiliary fuel in precedence to the main fuel injection. CONSTITUTION:Auxiliary fuel is supplied at first, and then a subbody 4 is raised by the auxiliary fuel acting onto the pressure receiving surface 11 in a fuel reservoir part 10, and pilot injection is carried out at an auxiliary injection port 3 and a main injection port 2. At this time, a needle 7 rises together with the subbody 4 in the state where the opening port 5 of the needle 7 is closed. Then, the switching to the main-fuel supply is carried out, and the subbody 4 lowers, and a seat surface 6 closes the auxiliary injection port 3. The needle 7 is raised by the main fuel pressure acting onto the pressure receiving surface 13 in a fuel reservoir part 12, and the opened port 5 is perfectly opened through the relative shift due to the lowering of the subbody 4. Therefore, the main fuel performs main injection from the main injection port 2, passing through the opening port 5.
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