Fuel injection valve

Abstract

In a fuel injection valve in which a funnel-shaped fuel collecting recessis provided between a valve seatand an outlet hole, and a flat fuel diffusion chamberwhich diffuses a fuel radially outward and guides the fuel to a plurality of fuel injection holesis provided between opposed surfaces of a valve seat memberand an injector plate, a seating portionhaving a spherical band shape, and a valve tip end portionwhich projects into a cone shape toward a center of the outlet holefrom the seating portionand leaves its top portion in the outlet holeeven at the time of valve opening of a valve bodyare formed at the valve body, a cone angle α of the valve tip end portionis set to be larger than a funnel angle β of the fuel collecting recess, and an inner peripheral surfaceA of the outlet holeis formed along an inner peripheral side curved surface of a virtual torus T so that the inner peripheral surface is connected to a bottom surface of the fuel collecting recessand a ceiling surface of the fuel diffusion chamber. Thus, generation of eddies at the time of reverse of the fuel flow in the outlet hole of the valve seat member is prevented to reduce pressure loss of the fuel, thereby suppressing decrease in the amount of injected fuel, promoting atomization of the injected fuel and stabilizing spray forms.