US 6,192,324 B1 · On-board diagnosis of emissions from catalytic converters

Abstract

This invention is an on-board means to verify that a vehicle's exhaust emissions control system functions normally. It monitors hydrocarbon (HC) exhaust emissions for a few minutes after a cold start or at other selected times. If used from cold start, it is an on-board approximation to taking the first bag sample in an FTP test. The measurement involves storing a portion of the exhaust HC. Various embodiments are discussed. Some involve measuring the cumulative amount of stored HC (as on a substrate) during the test. Other embodiments wait until the end of the test to measure the amount of stored HC. At the end of each test (or trip), the storage means is returned to an empty state to await the next test. If HC is stored on or in a substrate, for example, the temperature of the substrate is raised. This decreases the amount of stored HC vapor and renews the substrate for the next test.

Claims7

Dependent claims

A method for on-board diagnosis of emissions from a catalytic converter operatively connected to an internal combustion engine of a motor vehicle, comprising:

sampling a first portion of engine exhaust from the catalytic converter, where a remainder of the engine exhaust passes simultaneously from the motor vehicle;
adsorbing hydrocarbons from the portion of the engine exhaust onto a temperature controlled substrate;
electrically heating the substrate, thereby vaporizing substantially all of the hydrocarbons on the substrate;
quantifying the amount of hydrocarbons released from the substrate;
and
determining a malfunction in the catalytic converter when the amount of hydrocarbons exceeds a predetermined threshold.

3 more elements

Dependencies are inferred from the claim text.

On-board diagnosis of emissions from catalytic converters

Life of this patent

On-board diagnosis of emissions from catalytic converters

Life of this patent

Abstract

Claims7