Method for verifying the tightness of a tank bleeding system without using a pressure sensor

US8127596B2 · kind B2 · utility

Assignee

• CONTINENTAL AUTOMOTIVE GMBH · DE

Inventors

• Oliver Grunwald · Hockenheim, DE
• Alexander Ketterer · Nittendorf, DE

Key dates

• Filing date: Oct 19, 2006
• Grant date: Mar 6, 2012
• Expiry date: Dec 6, 2028

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02M25/0809
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

In a method for verifying the tightness of a tank bleeding system with a tank bleeding valve, a stop valve for air-tightly closing the tank bleeding system relative to an atmosphere prevailing outside the motor vehicle, and a bistable pressure switch whose switched condition indicates whether a predefined switching pressure is exceeded or not reached in the tank bleeding system, in order to be able to determine the tightness of the tank bleeding system without using a pressure sensor, the following steps are carried out: waiting until the vehicle speed drops below a certain threshold; opening the tank bleeding valve; closing the tank bleeding valve when a negative pressure has been attained which lies below the switching pressure; measuring the duration from the time an initial pressure lies below the switching pressure until the moment the switching pressure is exceeded again; and assessing the tightness is assessed based on the measured duration.