| 摘要 |
PURPOSE:To make injection pressure higher at the end of injection than at the beginning of injection, and maintain an injection start timing constant, by biasing a check valve and a needle valve with different springs. CONSTITUTION:When a needle valve 26 is lifted, fuel in a damper chamber 36 is pressurized by a rod 31. As flow of the fuel in the damper chamber 36 is limited by a restriction 38, injection is gently started. Pressure in accumulator chambers 16 and 17 has been alreadly increased by fuel in the accumulator chambers 16 and 17 and fuel from an injection pump 2, and an injection rate is gradually increased. At the end of supply of the fuel from the injection pump 2, pressure in a check valve chamber 19 is reduced, and a check valve 20 closes a fuel passage 25. As an internal volume of the damper chamber 36 is increased to be reduced in pressure, the needle valve 26 is further lifted to maximize the injection rate. |
