Patent ID: 9562503
Date: 2017-02-07
CPC Classifications: F02M

Claim:
1. A fuel injection nozzle comprising: a nozzle body being a cylindrical shape; a needle received in the nozzle body, the needle being slidable relative to an inner periphery of the nozzle body in an axial direction of the nozzle body, wherein the inner periphery of the nozzle body includes a seat surface, the needle includes a seat portion, the seat portion is removed from or seated on the seat surface to start or stop a fuel injection using an injection port disposed at a tip end side of the seat surface in the axial direction, the seat surface is a tapered shape, a diameter of the seat surface is reduced toward the tip end side of the seat surface in the axial direction, a sack chamber is disposed at a position adjacent to the tip end side of the seat surface, the sack chamber includes an inlet of the injection port, a sack surface defining the sack chamber includes a side surface and a bottom surface, the side surface has a sharper slope than the seat surface and is coaxial with the seat surface, the bottom surface is a curved shape and covers the sack chamber at a tip end side of the side surface in the axial direction, the side surface and the bottom surface are connected to each other, a part of the needle which is adjacent to a tip end side of the seat portion is a cone having a diameter reduced toward a tip end side of the cone in the axial direction, in a cross section including an axis of the nozzle body and an axis of the injection port, the seat surface and the side surface from one curved surface, and when the seat portion is seated on the seat surface, an end of the needle protrudes to a position in the sack chamber where the end of the needle is opposite to the inlet in a radial direction of the nozzle body.