Fuel injection nozzle for DME fuel, and diesel engine including the fuel injection nozzle for DME fuel

摘要

An existing diesel engine vehicle of light oil fuel is enabled to run as a diesel engine vehicle using DME as fuel without exchanging a whole diesel engine and at very low cost and easily. The shape of a tip part 21 of a needle valve 2 is set by a center diameter L 3 for regulating a minimum flow path area at full lift of a fuel injection nozzle 1 , a seat diameter L 2 of a seat part 211 coming in contact with a valve seat part 33 and blocking communication with a fuel injection hole 31 , and a shaft diameter L 1 , and a tip end angle is about 92 degrees. The center diameter L 3 is set to phi2.5 mm, the seat diameter L 2 is set to phi3.0 mm, and the shaft diameter L 1 is set to phi3.25 mm. The ratio of the center diameter L 3 and the seat diameter L 2 is L 3 /L 2 =2.5 mm/3.0 mm=about 0.833, and the ratio of the seat diameter L 2 and the shaft diameter L 1 is L 2 /L 1 =3.0 mm/3.25 mm=about 0.92.