Method for regenerating a particulate filter in the exhaust system of a gasoline engine

Patent metadata

Field	Value
Publication number	US-10907518-B2
Application number	US-201916521075-A
Country	US
Kind code	B2
Filing date	Jul 24, 2019
Priority date	Jul 24, 2018
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

A method for regenerating a particulate filter in an exhaust system of an internal combustion engine, wherein it is thereby provided that the quantity of overrun air in the overrun operation of the combustion engine be adapted to the air required for oxidizing the soot trapped in the particulate filter to achieve a rapid and efficient regeneration of the particulate filter, and it is provided that a throttle valve be opened in overrun operation to an extent that allows a maximum permissible soot conversion without risking thermal damage to the particulate filter.

First claim

The invention claimed is:

1. A method for regenerating a particulate filter in an exhaust system of a combustion engine, the particulate filter being regenerated in an overrun phase of the combustion engine, comprising the following steps:
determining a saturation condition of the particulate filter;
heating the particulate filter to a regeneration temperature;
computing a quantity of oxygen needed for regenerating the particulate filter; and
adapting the quantity of overrun air to the quantity of oxygen needed for regenerating the particulate filter;
increasing the quantity of overrun air by modifying the position of the throttle valve; and
opening the throttle valve in overrun operation to an extent that allows a maximum soot conversion on the particulate filter.

2. The method for regenerating a particulate filter as recited in claim 1 , further comprising increasing the quantity of overrun air by opening the throttle valve when the particulate filter has reached a lower threshold temperature.

3. The method for regenerating a particulate filter as recited in claim 2 , wherein the lower threshold temperature is within the range of 550° C. 600° C.

4. The method for regenerating a particulate filter as recited in claim 1 , further comprising reducing the quantity of overrun air by closing the throttle valve in response to the particulate filter reaching an upper threshold temperature.

5. The method for regenerating a particulate filter as recited in claim 1 , further comprising regenerating the particulate filter in a plurality of incremental steps.

6. The method for regenerating a particulate filter as recited in claim 5 , wherein heating phases for the particulate filter are provided in each instance between the individual incremental steps.

7. The method for regenerating a particulate filter as recited in claim 5 , further comprising operating the combustion engine between two overrun phases at a fired operating point.

8. The method as recited in claim 7 , wherein the fired operating point includes internal engine heating measures.

9. The method as recited in claim 8 , wherein the internal engine heating measures include an ignition-timing retard of the ignition point of the spark plugs or a lambda split operation.

10. The method as recited in claim 5 , wherein the particulate filter includes an electrical heating element, or an electrical heating element is connected upstream of the particulate filter, the electrical heating element being activated during regeneration of the particulate filter to prevent cooling of the particulate filter below a regeneration temperature in overrun operation.

11. A motor vehicle comprising:
a combustion engine that comprises an air supply system in which a throttle valve is disposed in an intake duct,
an exhaust system, in which a particulate filter is disposed, and
an engine control unit that is adapted for implementing a method according to claim 1 upon execution of a machine-readable program code.

Assignees

• Volkswagen Ag

Inventors

• Heinken Sebastian
• Thaler Tim
• Misiek Pierre
• Steinbrecher Christian

Classifications

• F01N3/023 Primary

  using means for regenerating the filters, e.g. by burning trapped particles · CPC title

• F02D41/12

  for deceleration {(F02D41/0005, F02D41/107 take precedence)} · CPC title

• F01N2900/1606

  Particle filter loading or soot amount · CPC title

• F01N9/002 Primary

  of filter regeneration · CPC title

• F01N2260/04

  for regeneration or reactivation, e.g. of catalyst · CPC title