FLUID INJECTION DEVICE

摘要

The invention relates to an injector comprising a nozzle that includes an opening and a seat, a needle movably mounted in the nozzle and having an end defining a valve in a contact area with the seat, a means for vibrating the valve, a first acoustic-impedance breaking area at a first distance from the valve along the nozzle, and another first acoustic-impedance breaking area at a second distance from the valve along the needle. According to the invention, each of the first and second distances is such that the respective propagation time of acoustic waves along said distance is: Ti = ni *[?/2], where r// is a positive integer coefficient different from zero with i = 3 for the first distance and i = 4 for the second distance, ? being a period of the vibrations.