Fuel injection pump

US5243943A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gunter Bofinger · Leinfelden, DE
• Heinz Nothdurft · Stuttgart, DE
• Karl-Friedrich Russeler · Ditzingen, DE
• Josef Hain · Leonberg, DE
• Hubertus Zedler · Nußdorf, DE
• Manfred Narr-Hess · Fellbach, DE
• Remy Schmitt · Pau, FR

Key dates

• Filing date: Aug 18, 1992
• Grant date: Sep 14, 1993
• Expiry date: Aug 18, 2012

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D2001/186
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A distributor-type fuel injection pump is provided with a hydraulic injection adjusting mechanism whose injection adjusting piston adjusts the cam gear unit for driving the pump plunger to execute strokes corresponding to the desired position of the start of injection. The injection adjusting piston defines a control space on one side and a spring space receiving a return spring on the other side. The control space is connected via a throttle bore with the pump interior space which is filled with fuel by a delivery pump. The fuel pressure is adjusted by a pressure control valve. To prevent unstable pressure vibrations on the injection adjusting piston, which leads to defects in the operation of the fuel injection pump, the spring space is connected on one side with the suction side of the delivery pump via a first throttle and on the other side with the pressure side of the delivery pump via a second throttle having a smaller throttle cross section.