Gasoline particulate filter temperature control

Abstract

Methods and systems are provided for controlling particulate filter temperature during non-combustion conditions. In one example, a method for an engine includes responsive to a particulate filter temperature above a threshold temperature and while operating the engine with deceleration fuel shut-off (DFSO), fully closing a throttle valve configured to regulate flow of intake air to the engine, and responsive to intake manifold pressure dropping below a threshold pressure while the throttle valve is fully closed, adjusting a position of the throttle valve based on the particulate filter temperature.

Description

technical field [0001] The present specification generally relates to methods and systems for reducing airflow to a gasoline particulate filter while extending deceleration fuel cut-off time of an engine. Background technique [0002] The fuel consumption of a car engine can be improved by cutting off fuel delivery to the engine when the vehicle is decelerating. This is known as deceleration fuel cutoff (DFSO). However, during DFSO, the delivery of oxygen to the vehicle's emission control devices increases. In vehicles that include a particulate filter, increased oxygen delivery may lead to filter degradation due to overheating of the filter. [0003] US Patent 8,407,988 provides a method of reducing oxygen flow to the particulate filter during non-combustion conditions by closing the intake throttle valve. However, the inventors herein have recognized a problem with the above approach. As the engine continues to spin with the intake throttle valve closed, intake manifol...

AI Technical Summary

Problems solved by technology

If MAP becomes too low, engine degradation may occur, for example, lubricant may be drawn into the combustion chamber

Images