Patent ID: 7044405

Claim:
A fuel injector comprising: a fuel passage, a valve disposed on the fuel passage, a valve seat that receives the valve, a jet opening having a diameter D 2 , the jet opening is formed in the valve seat and through which fuel is exhausted, the jet opening being opened when the valve is moved apart from the valve seat, and a jet opening downstream channel having a diameter D 1 and extending downstream from the jet opening through the valve seat and communicates the jet opening to the outside, wherein the diameter D 1 of the jet opening downstream channel is double the diameter D 2 of the jet opening at least in a region right below the jet opening, a first channel and a second channel within the jet opening downstream channel, wherein the second channel is downstream said first channel and is continuously and smoothly connected to the first channel, said first channel has a constant diameter, while the second channel is conically enlarged away from the jet opening, and wherein the diameter D 1 of the jet opening downstream channel being arranged and adapted such that the valve seat has a wall thickness to prevent leakage of noise to the outside through the valve seat, which noise is caused by contact of the valve with the valve seat.