Method and device for varying the supply pressure applied to a high pressure pump and generated by a low pressure pump

US6708671B1 · kind B1 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Klaus Joos · Walheim, DE
• Jens Wolber · Gerlingen, DE
• Thomas Frenz · Nördlingen, DE
• Hansjoerg Bochum · Leinfelden, DE
• Markus Amler · Rutesheim, DE

Key dates

• Filing date: May 28, 2002
• Grant date: Mar 23, 2004
• Expiry date: May 28, 2022

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D2250/02
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

Method for varying a prepressure (p_des) generated by a low-pressure pump and applied to a high-pressure pump with the low-pressure pump (2) and the high-pressure pump (3) pumping fuel for the internal combustion engine (1). In order to keep the prepressure (p_des), on the one hand, as low as possible to take load off the low-pressure pump (2) and to, on the other hand, adjust the prepressure (p_des) so high that a vaporization of the fuel is reliably avoided, the invention suggests that: the actual temperature (T_Krst) of the fuel in the high-pressure pump (3) is determined; a prepressure (p_des) as low as possible is determined in dependence upon the fuel temperature (T_Krst) for which a vaporization of the fuel in the high-pressure pump (3) is reliably avoided; and, the low-pressure pump (2) is so driven or controlled that it generates the determined prepressure (p_des). The method is preferably carried out on the basis of physical models of the high-pressure pump (3).