Secondary air feeding apparatus and method of detecting abnormality in the apparatus
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsShigemasa Hirooka, Mamoru Yoshioka
Life of this patent
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Abstract
The invention relates to a secondary air feeding apparatus and a method of detecting an abnormality in the apparatus capable of making a precise determination on abnormalities in components and detecting operational failures as well. According to one aspect of the invention, the opening-closing state of opening-closing means (ASV) is switched during the operation of an air pump, and abnormalities in respective components are detected on the basis of pressure values and pressure fluctuation values detected by a pressure sensor disposed between the air pump and the ASV before and after the switching of the opening-closing means.
Claims22
A secondary air feeding apparatus, comprising:
- a secondary air feeding passage that supplies secondary air to a region upstream of an exhaust gas purification unit of an internal combustion engine;
- an air pump disposed in the secondary air feeding passage;
- an opening-closing portion which is disposed downstream of the air pump and which switches an opening-closing state of the secondary air feeding passage;
- a pressure sensor disposed between the air pump and the opening-closing portion, wherein the pressure sensor outputs pressure values;
- and
- an abnormality detection portion that detects abnormalities in components on the basis of an average of the pressure values, wherein the average is calculated based on the output pressure values detected by the pressure sensor within a predetermined period, before and after the switching of the opening-closing state of the opening-closing portion as detected by the pressure sensor during the operation of the air pump and on the basis of a difference between the average pressure values.
A secondary air feeding apparatus, comprising:
- a secondary air feeding passage that supplies secondary air to a region upstream of an exhaust gas purification unit of an internal combustion engine;
- an air pump disposed in the secondary air feeding passage;
- an opening-closing portion which is disposed downstream of the air pump and which switches an opening-closing state of the secondary air feeding passage by means of an opening signal and a closing signal;
- a pressure sensor disposed between the air pump and the opening-closing portion;
- and
- an abnormality detection portion that detects, during the operation of the air pump, abnormalities in components of the secondary air feeding apparatus on the basis of an opening pressure value detected by the pressure sensor as a pressure value, after the receipt of the opening signal in the opening-closing portion, a closing pressure value detected by the pressure sensor as a pressure value after the receipt of the closing signal in the opening-closing portion, and a difference between the opening pressure value and the closing pressure value;
- wherein the opening pressure value and the closing pressure value are averages of pressure values detected by the pressure sensor within a predetermined period.
A secondary air feeding apparatus, comprising:
- a secondary air feeding passage that supplies secondary air to a region upstream of a plurality of exhaust gas purification units that are arranged in association with one or more cylinders of a multi-cylinder internal combustion engine;
- a main passage forming an upstream portion of the secondary air feeding passage;
- a plurality of branch passages forming a downstream portion of the secondary air feeding passage;
- an air pump disposed in the main passage;
- opening-closing portions which is disposed in the branch passages respectively and which switches opening-closing states of the branch passages respectively;
- a pressure sensor disposed downstream of the air pump in the main passage, wherein the pressure sensor outputs pressure values;
- and
- an abnormality detection portion that switches opening-closing states of the opening-closing portions one by one during the operation of the air pump and that detects abnormalities in components on the basis of an average of the pressure values, wherein the average is calculated based on the output pressure values detected by the pressure sensor within a predetermined period, before and after the switching of each of the opening-closing portions and a difference between the pressure values.
A secondary air feeding apparatus, comprising:
- a secondary air feeding passage that supplies secondary air to a region upstream of a plurality of exhaust gas purification units that are arranged in association with one or more cylinders of a multi-cylinder internal combustion engine;
- a main passage forming an upstream portion of the secondary air feeding passage;
- a plurality of branch passages forming a downstream portion of the secondary air feeding passage;
- an air pump disposed in the main passage;
- opening-closing portions which is disposed in the branch passages respectively and which switches opening-closing states of the branch passages respectively by means of an opening signal and a closing signal;
- a pressure sensor disposed downstream of the air pump in the main passage;
- and
- an abnormality detection portion that detects, during the operation of the air pump, abnormalities in components of the secondary air feeding apparatus on the basis of an opening pressure value detected by the pressure sensor as a pressure value after the receipt of the opening signal in each of the opening-closing portions and a closing pressure value detected by the pressure sensor as a pressure value after the receipt of the closing signal in each of the opening-closing portions, wherein the opening pressure value and the closing pressure value are averages of pressure values detected by the pressure sensor within a predetermined period.
A method of detecting an abnormality in a secondary air feeding apparatus including a secondary air feeding passage that supplies secondary air to a region upstream of an exhaust gas purification unit of an internal combustion engine, an air pump disposed in the secondary air feeding passage, an opening-closing portion which is disposed downstream of the air pump and which switches an opening-closing state of the secondary air feeding passage by means of an opening signal and a closing signal, and a pressure sensor disposed between the air pump and the opening-closing portion, comprising the step of:
- detecting, during the operation of the air pump, abnormalities in components of the secondary air feeding apparatus on the basis of an opening pressure value detected by the pressure sensor as a pressure value after the receipt of the opening signal in the opening-closing portion, a closing pressure value detected by the pressure sensor as a pressure value after the receipt of the closing signal in the opening-closing portion, and a difference between the opening pressure value and the closing pressure value, wherein the opening pressure value and the closing pressure value are averages of pressure values detected by the pressure sensor within a predetermined period.
A method of detecting an abnormality in a secondary air feeding apparatus including a secondary air feeding passage that supplies secondary air to a region upstream of a plurality of exhaust gas purification units that are arranged in association with one or more cylinders of a multi-cylinder internal combustion engine, a main passage forming an upstream portion of the secondary air feeding passage, a plurality of branch passages forming a downstream portion of the secondary air feeding passage, an air pump disposed in the main passage, opening-closing portion which is disposed in the brunch passages respectively and which switches opening-closing states of the branch passages respectively, and a pressure sensor disposed downstream of the air pump in the main passage, comprising the step of:
- detecting, during the operation of the air pump, abnormalities in components of the secondary air feeding apparatus on the basis of an opening pressure value detected by the pressure sensor as a pressure value after the receipt of the opening signal in each of the opening-closing portions and a closing pressure value detected by the pressure sensor as a pressure value after the receipt of the closing signal in each of the opening-closing portions,
- wherein the opening pressure value and the closing pressure value are averages of pressure values detected by the pressure sensor within a predetermined period.
Dependencies are inferred from the claim text.