Fuel injection nozzle with a member to reduce the frictional force developed between parts during the clamping

摘要

In a fuel injection nozzle 1 for an internal combustion engine, a frictional force reducing member 9 is interposed between a seating surface 36 of a shoulder portion 31 of a nozzle body 3 and an inner seating surface 32 of a bearing portion 33 of a retaining nut 6, whereby a frictional force developed between both seating surfaces 36 and 32 can be diminished without performing a high-degree of surface machining on the inner seating surface 32 of a bearing portion 33 of the retaining nut 6, even if the surface roughness of the inner seating surface 32 of a bearing portion of the retaining nut 6 is large. Consequently, it is possible to prevent deformation of a slide portion 7 of the nozzle needle 2 which is attributable to a twist of the nozzle body 3 caused by frictional force.