| 摘要 |
PURPOSE:To reduce an engine noise in a way of preventing a Diesel knock from occurring, by injecting a small quantity of fuel via an orifice passage at the initial stage of injection and then injecting a large quantity of fuel instead via a main passage upon piston valve switching. CONSTITUTION:In time of driving an internal-combustion engine, a piston valve 43 is energized by dint of a spring 45, closing its first port 37. From this condition, when a plunger 23 goes up as driving by a cam 24, a pump chamber 29 is cut off from an inlet port 28 and the combustion pressure therefore suddenly rises. With a rise in the piston valve 43, fuel inside a spring chamber 44 is compressed to some extent and flows out to an injection nozzle from a nozzle port 39 via an orifice passage 42. Afterward, when the piston valve 43 opens its first port 37, the fuel pressurized by the plunger 23 is fed by pressure in large quantities to the injection nozzle via an oil passage 36 so that the quantity of fuel suddenly grows large. |
