FUEL INJECTION SYSTEM HAVING LOW NOISE

摘要

PURPOSE: A fuel injector of low noise type is provided to reduce shock noise in a collision between a needle for fuel injection and a needle seat by adopting a shock absorber unit at the needle or the needle seat. CONSTITUTION: A needle colliding part or a needle seat colliding part of a fuel injector is made by material having excellent softness, including heavy metals of gold, silver, platinum or copper, or polymer material of rubber. The colliding part is coated by plating in the case of heavy metals. The coating material(70) absorbs a shock in a collision between a needle and a needle seat by the excellent softness. Thereby, shock noise in fuel injection is reduced remarkably. The needle colliding part or the needle seat colliding part has a groove for mounting an O-ring having a diameter not disturbing fuel injection. The O-ring absorbs a shock in a collision between the needle and the needle seat of the fuel injector. Therefore, the shock noise is reduced remarkably.