Air-fuel ratio control apparatus and air-fuel ratio control method for internal combustion engine

Inactive Publication Date: 2010-09-02
TOYOTA JIDOSHA KK
View PDF5 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0011]The invention provides an air-fuel ratio control apparatus and an air-fuel ratio control method for an internal combusti

Problems solved by technology

However, recently, it has been found that the air-fuel ratio of the exhaust gas flowing into the catalyst as well as the deterioration of the catalyst influences the decrease in the level of the oxygen storage capacity of the catalyst.
However, it takes time to sufficiently recover the level of the oxygen storage capacity.
Thus, until the level of the oxygen s

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Air-fuel ratio control apparatus and air-fuel ratio control method for internal combustion engine
  • Air-fuel ratio control apparatus and air-fuel ratio control method for internal combustion engine
  • Air-fuel ratio control apparatus and air-fuel ratio control method for internal combustion engine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0025]Hereinafter, an embodiment of the invention will be described with reference to the accompanying drawings. FIG. 2 is a schematic diagram showing an internal combustion engine system that includes an air-fuel ratio control apparatus according to the embodiment of the invention. As shown in FIG. 2, an internal combustion engine 2 is connected to an exhaust passage 4. Two catalysts 6 and 8, which purify pollutants (NOx, CO, and HC) in exhaust gas, are disposed in the exhaust passage 4. At least the catalyst 6 on an upstream side has oxygen storage capacity. It is to be understood that “storage” used herein means retention of a substance (solid, liquid, gas molecules) in the form of at least one of adsorption, adhesion, absorption, trapping, occlusion, and others. The catalyst 6 on the upstream side is disposed close to an exhaust manifold (not shown). The catalyst 8 on a downstream side is disposed under the floor of a vehicle. A linear air-fuel ratio sensor 12 is installed upstr...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A fuel injection amount is controlled so that the air-fuel ratio of exhaust gas flowing into a catalyst (6) oscillates around a stoichiometric air-fuel ratio. When it is estimated that the level of oxygen storage capacity of the catalyst (6) is lower than a predetermined reference capacity, the amplitude of the air-fuel ratio of the exhaust gas which oscillates around the stoichiometric air-fuel ratio is reduced by controlling the fuel injection amount. The level of the oxygen storage capacity of the catalyst (6) is estimated based on the amplitude of the output signal from an oxygen sensor (14) disposed downstream of the catalyst (6).

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The invention relates to an air-fuel ratio control apparatus and an air-fuel ratio control method for an internal combustion engine that includes a catalyst, disposed in an exhaust passage, which has oxygen storage capacity.[0003]2. Description of the Related Art[0004]Japanese Patent Application Publication No. 5-321721 (JP-A-5-321721) describes an example of an air-fuel ratio control apparatus that includes a linear air-fuel ratio sensor disposed upstream of a catalyst, and an oxygen sensor disposed downstream of the catalyst. The air-fuel ratio control apparatus controls an air-fuel ratio based on signals output from the two sensors. The linear air-fuel ratio sensor has a linear output characteristic in which an output linearly changes in proportion to the air-fuel ratio. The oxygen sensor outputs a signal according to the concentration of oxygen in gas. The oxygen sensor has an output characteristic in which the outp...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): F01N11/00F01N3/10F01N9/00
CPCF01N2570/16F02D41/027F02D2200/0814F02D41/1454F02D41/0295
Inventor FUJIWARA, TAKAHIKONAKAGAWA, NORIHISAKATO, NAOTOOKAZAKI, SHUNTAROIDE, KOJI
Owner TOYOTA JIDOSHA KK
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap