| 摘要 |
PURPOSE:To improve the expansion of fuel spray by shaping a nozzle spout of a fuel valve to expand the sectional area between a nozzle bag part and a nozzle spout exit on the way and selecting the expanding rate in the axial direction of a combustion chamber to be greater than that in the vertical direction to the axis. CONSTITUTION:In a direct injection type Diesel engine, a nozzle spout 12 of a fuel valve is shaped to be a round hole of a diameter (d) in a contacting part with a nozzle top 7, and expanded to be staged at a point of a distance (1l') from an entrance to an exit on the side of a combustion chamber 10. That is, in the vertical direction to the axis of the combustion chamber 10, it takes a size b1 equivalent to or a little greater than the said diameter (d), and in the axial direction of the combustion chamber 10, it is shaped into a rectangle to have a longer side a1 than the size b1. Meanwhile, in the above-said exit 10, it is shaped into a rectangle with a short side b2 and a long side a2 to set relations b2>=b1 and a1>=a2(a2-a1)>(b2-b1). This construction permits to improve the expansion of fuel spray to increase the contact area with swirls, and improve the capacity of an engine. |
