Fuel injection pump

US5538397A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Helmut Laufer · Gerlingen, DE
• Anton Karle · Villingen-Schwenningen, DE

Key dates

• Filing date: Sep 23, 1993
• Grant date: Jul 23, 1996
• Expiry date: Sep 23, 2013

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D41/3082
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A fuel injection pump has a pump plunger (13), which is driven by a drive shaft (15) via a cam gear (14) at least in an axial stroke movement and in so doing generates a fuel injection pressure in a pump work space (16), and a magnet valve (30) blocking or releasing the pump work space (16) relative to a relief duct (26). The start of delivery of the pump plunger is determined by the closing of the relief duct (26) and the end of delivery of the pump plunger (13) is determined by the release of the relief duct (26). To prevent the so-called jumping off of the plunger in the cam gear (14), the magnet valve (30) is controlled after the end of delivery in such a way that a residual pressure lying below the injection pressure is built up in the pump work space (16) until the top dead center point is reached (FIG. 1).