Method for monitoring a tank venting system that traps fuel vapors and feeds them to an internal combustion engine

• US 5,499,613 A
• Filed: 07/21/1994
• Issued: 03/19/1996
• Est. Priority Date: 07/21/1993
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Pfleger, Hartmut, Bayerle, Klaus
• Primary Examiner(s): Moulis, Thomas N.
• Application Number:
  US08/278,272
• Time in Patent Office: 607 Days
• Field of Search: 123/518, 123/519, 123/520, 123/198 D
• US Class Current: 123/520
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system

Abstract

A tank venting system for trapping fuel vapors and feeding the fuel vapors to an internal combustion engine having a fuel tank and an intake tube, includes a container adsorbing fuel vapors. A venting line is connected between the fuel tank and the container. A regeneration line is connected between the container and the intake tube of the internal combustion engine. A ventilation line communicates with the atmosphere and the container. A ventilation valve closes the ventilation line. A tank venting valve is disposed in the regeneration line and is triggered in an opening direction for feeding fuel vapors stored in the container. A pressure sensor detects a system pressure of the tank venting system. A method for monitoring the tank venting system includes monitoring the system pressure with the pressure sensor during the feeding of the fuel vapors, categorizing the ventilation valve as functioning improperly if a predetermined pressure threshold value is exceeded, and closing the tank venting valve.

Claims

1. In a method for monitoring a tank venting system for trapping fuel vapors and feeding the fuel vapors to an internal combustion engine having a fuel tank and an intake tube, wherein the tank venting system includes:

a container adsorbing fuel vapors, a venting line connected between the fuel tank and the container, a regeneration line connected between the container and the intake tube of the internal combustion engine, a ventilation line communicating with the atmosphere and the container, a ventilation valve for closing the ventilation line, a tank venting valve being disposed in the regeneration line and being triggered in an opening direction for feeding fuel vapors stored in the container, and a pressure sensor detecting a system pressure of the tank venting system,

the improvement which comprises;

monitoring the system pressure with the pressure sensor during the feeding of the fuel vapors;

categorizing the ventilation valve as functioning improperly if the system pressure determined in the monitoring step exceeds a predetermined pressure threshold value; and

closing the tank venting valve.

2. The method according to claim 1, which comprises starting a time counter if the threshold value is exceeded;

and closing the tank venting valve if a predeterminable final counter value is attained.