Fuel injection nozzle for internal combustion engines

摘要

PCT No. PCT/DE86/00159 Sec. 371 Date Dec. 15, 1986 Sec. 102(e) Date Dec. 15, 1986 PCT Filed Apr. 11, 1986 PCT Pub. No. WO87/00889 PCT Pub. Date Feb. 12, 1987.Fuel injection nozzle for internal combustion engines includes a nozzle element having a front cusp formed with a conical valve seat face. At least one injection hole is provided in the front cusp. The outer wall area of the front cusp which is disposed opposite to the valve seat face has a lower hardness than that of the inner wall area forming the valve seat face. When the injection hole extends from a pocket hole, preferably the outer wall area of the front cusp encompassing the picket hole has a lower hardness than that of the opposite disposed inner wall area. The intermediary center wall area preferably has a still lower hardness than the outer wall area. Thus, it is achieved that the front cusp of the nozzle element has a higher rigidity than in a known embodiment, without the valve seat face losing any hardness or that the protection of the outer wall area of the front cusp being unduly severly reduced against abrasive wear.