FUEL INJECTION NOZZLE

PROBLEM TO BE SOLVED: To prevent lowering of a flow rate coefficient even when an injection pressure is increased, in a fuel injection nozzle for injecting a fuel into an internal combustion engine.SOLUTION: In a nozzle including a first structure, for example, a cone angle is determined so as to satisfy an inequality 100°≤ ≤194°, so that a flow rate coefficient Cd can be made 0.82 or more even when an injection pressure is increased to 220 MPa. Further by determining the cone angle so as to satisfy an inequality 100°≤ ≤186°, the flow rate coefficient Cd can be made 0.82 or more even when the injection pressure is increased to 240 Mpa. Furthermore by determining the cone angle so as to satisfy an inequality 100°≤ ≤175°, the flow rate coefficient Cd can be made 0.82 or more even when the injection pressure is increased to 260 Mpa.