US Patent 7784716 Fuel injection valve and method for manufacturing swirler

A valve seat 14 having an injection hole 14b is fixed at one end of a hollow valve main body 15, a valve body 12 slidably supported so as to be separated from and brought into contact with the valve seat 14 to open and close the injection hole 14b and a swirler 16 for surrounding the valve body 12 to slidably support the valve body 12 and for imparting a swirling motion to fuel flowing into the injection hole 14b are equipped, a swirling groove 16b in the swirler 16 includes a curvature part 16b3 in a groove outlet, and a sectional configuration of the swirling groove 16b is constituted so that the depth of the central part is larger than the depth of the end part.