Fuel injection nozzle for internal combustion engines

US4801095A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Werner Banzhaf · Sindelfingen, DE
• Ewald Eblen · Stuttgart, DE
• Heinrich Faber · Stuttgart, DE
• Rolf J. Giersch · Eberdingen, DE
• Karl Hofmann · Neckarrems, DE
• Dieter Liedtke
• Helmut Norberg · Stuttgart, DE

Key dates

• Filing date: Dec 15, 1986
• Grant date: Jan 31, 1989
• Expiry date: Dec 15, 2006

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49432
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

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.