Patent · US Expired

Method for monitoring a system for delivering secondary air to the exhaust gas of an internal combustion engine

US5526642A · kind A · utility

5Cited by

3References

1Claims

0Family size

Assignee

Robert Bosch GmbH · DE

Inventors

Dieter-Andreas Dambach · Ditzingen, DE
Rainer Frank · Sachsenheim, DE
Manfred Mezger · Markgröningen, DE

Key dates

Filing date	Nov 18, 1994
Grant date	Jun 18, 1996
Priority date	—
Expiry date	Nov 18, 2014

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY02T10/40
WIPO fieldEnvironmental technology
WIPO sectorChemistry

Abstract

A method for monitoring a system for delivering secondary air to an exhaust tube of an internal combustion engine. In the method a secondary air pump is switched on and builds up a pressure on the inlet side of a blocking valve which is normally closed and not being acted upon. The blocking valve has a valve closing member that is acted upon by a predetermined closing force of an elastic element. If the secondary air quantity pumped by the secondary air pump reaches a certain minimum air quantity and pressure, then with the then-opened blocking valve, a lambda sensor disposed in an exhaust tube detects a change in the lambda value in the exhaust tube that exceeds a predetermined threshold value. The method is suitable for monitoring the function of a system for delivering secondary air to the exhaust tube of an internal combustion engine.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.