| Patent application number | Description | Published |
|---|
| 20090037079 | Air-fuel ratio control apparatus and method for an internal combustion engine - When an internal combustion engine including a plurality of cylinders is operating steadily, an index value relating to an actual hydrogen content in exhaust gas downstream of a portion where exhaust passages from the cylinders merge, and upstream of a catalyst is detected. When an index value relating to the actual hydrogen content in the exhaust gas is larger than a determination index value relating to a hydrogen content corresponding to a permissible limit of air-fuel ratio variation, it is determined that there is abnormal air-fuel ratio variation between the cylinders. | 02-05-2009 |
| 20090165440 | Catalyst Deterioration Monitoring System and Catalyst Deterioration Monitoring Method - A storage reduction NOx catalyst is disposed in an exhaust passage for an internal combustion engine. A NOx sensor is disposed upstream of the NOx catalyst. An inflow NOx amount, which is the amount of NOx that has flown into the NOx catalyst, is calculated by accumulating the output of the NOx sensor. A total storage amount, which is the sum of the amounts of oxygen and NOx stored in the NOx catalyst, is calculated based on an output generated by an exhaust gas sensor disposed downstream of the NOx catalyst when rich spike is being executed. The deterioration of the NOx catalyst is determined based on the inflow NOx amount and the total storage amount. | 07-02-2009 |
| 20090199543 | CATALYST MONITORING SYSTEM AND MONITORING METHOD - A catalyst monitoring system diagnoses deterioration of an NO | 08-13-2009 |
| 20090211350 | APPARATUS AND METHOD FOR DETECTING ABNORMALITY OF INTER-CYLINDER AIR-FUEL RATIO DISPERSION IN MULTI-CYLINDER INTERNAL COMBUSTION ENGINE - An apparatus or a method for detecting an abnormality of inter-cylinder air-fuel ratio dispersion in a multi-cylinder internal combustion engine according to the invention is equipped with a catalytic element that purifies exhaust gas of hydrogen, a first air-fuel ratio sensor that detects an air-fuel ratio of exhaust gas that has not passed through the catalytic element, a second air-fuel ratio sensor that detects an air-fuel ratio of exhaust gas that has passed through the catalytic element, a device that detects an abnormality of inter-cylinder air-fuel ratio dispersion on the basis of a divergence state of a detected value of a second air-fuel ratio to a lean side from a detected value of a first air-fuel ratio, and a device that forcibly reduces fuel injection amounts in cylinders individually when an abnormality on dispersion is detected by the abnormality detector, detects a divergence state of the detected value of the second air-fuel ratio to the lean side from the detected value of the first air-fuel ratio at this time, and specifies as an abnormal cylinder that one of the cylinders in which a value indicating this divergence state has become smaller than at a time of detection of the abnormality of dispersion. | 08-27-2009 |
| 20090260347 | APPARATUS AND METHOD FOR DETECTING ABNORMAL AIR-FUEL RATIO VARIATION AMONG CYLINDERS OF MULTI-CYLINDER INTERNAL COMBUSTION ENGINE - An apparatus and a method for detecting abnormal air-fuel ratio variation among cylinders of a multi-cylinder internal combustion engine are provided. The apparatus includes: a catalyst that is provided in an exhaust passage of the multi-cylinder internal combustion engine; a catalyst temperature detection unit that detects a temperature of the catalyst; a catalyst temperature estimation unit that estimates a temperature of the catalyst based on an engine operating state; and an abnormality detection unit that determines whether abnormal air-fuel ratio variation among the cylinders has occurred based on the detected temperature of the catalyst and the estimated temperature of the catalyst. | 10-22-2009 |
| 20090320454 | CATALYST MONITORING SYSTEM AND METHOD - A total amount of NOX that flows into an NOX catalyst between the time that air-fuel ratio control ends and the time that the air-fuel ratio control starts the next time, is obtained. A total stored amount, which is the sum of an oxygen stored amount and an stored amount in the NOX catalyst before the air-fuel ratio control started, is calculated based on the amount of reducing agent that has flowed into the NOX catalyst during the air-fuel ratio control. The oxygen stored amount is calculated by extrapolating a relationship between the total amount of NOX and the total stored amount. The relationship is established beforehand by executing the air-fuel ratio control with at least two levels. | 12-31-2009 |
| 20100018186 | FAULT DETECTION SYSTEM FOR PM TRAPPER - An object of the present invention is to provide a technology that enables detection of a fault of a PM trapper with improved accuracy. In the present invention, a pressure sensor | 01-28-2010 |
| 20100024520 | ABNORMALITY DIAGNOSIS APPARATUS FOR NOX SENSOR - An NOx catalyst of storage reduction type and an after-catalyst NOx sensor are provided in an exhaust passage in an internal combustion engine. The after-catalyst NOx sensor detects the NOx concentration on the downstream side of the NOx catalyst. The NOx concentration on the upstream side of the NOx catalyst is detected or estimated. The possible abnormality of the after-catalyst NOx sensor is determined by comparing the NOx concentration on the upstream side of the NOx catalyst detected or estimated and the NOx concentration detected by the after-catalyst NOx sensor, under the condition that the NOx catalyst does not substantially absorb NOx in exhaust gas. Abnormality diagnosis is performed with the possible impact of the NOx catalyst inhibited. | 02-04-2010 |
| 20100083637 | DEGRADATION DIAGNOSTIC APPARATUS FOR NOX CATALYST - A NOx amount capable of being absorbed by a criteria catalyst as a boundary between degradation and normality is supplied to a NOx storage reduction catalyst and thereafter, a reducer amount corresponding to the NOx amount is supplied by a rich spike operation. Degradation of the NOx catalyst is determined based upon the output of the NOx sensor at this time. Since the degradation of the NOx catalyst is determined only by a magnitude of the NOx sensor output, the degradation diagnosis can be performed with high precision. While the catalyst is normal, the excessive reducers are not supplied and therefore, deterioration of the fuel consumption can be prevented. | 04-08-2010 |
| 20100146936 | Catalyst Deterioration Detection Device - A catalyst deterioration detector not causing false detection of catalyst deterioration by eliminating the influence of a variation of the state of the gas at the catalyst outlet on the oxygen storage amount. Setting the lean target A/F to afL | 06-17-2010 |
| 20100186491 | ABNORMALITY DIAGNOSIS DEVICE FOR AIR-FUEL RATIO SENSOR - An abnormality diagnosis device according to the present invention can calculate a calculation air-fuel ratio A/Fk based upon a fuel injection quantity and an intake air quantity, and determine the abnormality of the air-fuel ratio sensor based upon the calculation air-fuel ratio and an actual air-fuel ratio detected by an air-fuel ratio sensor, when an operating condition in the internal combustion engine relatively rapidly changes according to an engine operating demand and thereby the calculation air-fuel ratio relatively rapidly changes. Since the air-fuel ratio is not forcibly changed and fluctuated, deterioration of the exhaust emission and the combustion state, and deterioration of the vibration and the noise at abnormality diagnosing can be certainly prevented. | 07-29-2010 |
| 20100199754 | MALFUNCTION DIAGNOSIS DEVICE FOR EXHAUST GAS PURIFICATION SYSTEM AND MALFUNCTION DIAGNOSIS METHOD THEREFOR - In a malfunction diagnosis device for an exhaust gas purification system including an exhaust gas purification catalyst disposed in the exhaust passage of an internal combustion engine, and a reductant supply device that supplies reductant to exhaust gas that flows in an upstream side of the exhaust gas purification catalyst, the degree of degradation of the exhaust gas purification catalyst is diagnosed by comparing the timing at which the bed temperature of the exhaust gas purification catalyst starts to rise due to the heat of moisture adsorption reaction, against a normal value. | 08-12-2010 |
| 20100211290 | ABNORMALITY DIAGNOSTIC DEVICE AND ABNORMALITY DIAGNOSTIC METHOD FOR MULTICYLINDER INTERNAL COMBUSTION ENGINE - A fuel injection amount from fuel injection valves is actively controlled and an input air-fuel ratio is caused forcibly to oscillate. A system from the fuel injection valves to the air-fuel ratio sensor is simulated by a first order delay system, and a gain and time constant are identified on the basis of the input air-fuel ratio relating to the model and an output air-fuel ratio obtained from the air-fuel ratio sensor. The presence of an air-fuel ratio abnormal variation is diagnosed on the basis of whether or not the identified values of the gain and the time constant are less than a first and second predetermined values respectively. | 08-19-2010 |
| 20100257922 | ABNORMALITY DIAGNOSIS APPARATUS AND ABNORMALITY DIAGNOSIS METHOD FOR NOx CATALYST - An abnormality diagnosis apparatus for an NOx catalyst of the present invention measures an index value (R) regarding an NOx clarification capacity of an NOx catalyst and determines an abnormality of the NOx catalyst based on index values (R | 10-14-2010 |
| 20100307135 | APPARATUS AND METHOD FOR DIAGNOSING CATALYST DETERIORATION - A catalyst deterioration diagnosing apparatus is provided with means for performing stoichiometric feedback control on the air-fuel ratio based on at least output from an upstream air-fuel ratio sensor provided upstream of a catalyst, means for measuring the oxygen storage capacity of the catalyst, and means for correcting the measured value of the oxygen storage capacity based on at least the output behavior of a downstream air-fuel ratio sensor provided downstream of the catalyst during the stoichiometric feedback control. The measured value of the oxygen storage capacity is corrected using the output behavior of the downstream air-fuel ratio sensor during stoichiometric feedback control. The diagnostic is performed after eliminating the effects from sulfur by correcting the measured value to a value corresponding to when low sulfur fuel is used, which makes it possible to prevent an erroneous diagnosis from being made. | 12-09-2010 |
| 20110000290 | ABNORMALITY DIAGNOSIS APPARATUS AND ABNORMALITY DIAGNOSIS METHOD FOR NOx SENSOR - An exhaust passage ( | 01-06-2011 |
| 20110054761 | CYLINDER-TO-CYLINDER AIR/FUEL RATIO IMBALANCE DETERMINATION SYSTEM OF INTERNAL COMBUSTION ENGINE - A cylinder-to-cylinder air/fuel ratio imbalance determination system obtains an imbalance determination parameter that increases or decreases as a difference between the air/fuel ratios of different cylinders increases, based on output values of an air/fuel ratio sensor, and makes a cylinder-to-cylinder A/F imbalance determination, based on the result of comparison between the imbalance determination parameter and a threshold value for imbalance determination. The determination system changes the amount of fuel injected into one or more of the cylinders so as to create a forced imbalance condition in which the air/fuel ratio of a particular cylinder deviates from the air/fuel ratio of the remaining cylinders, and obtains an air/fuel ratio sensor evaluation parameter (e.g., rate of change ΔAF of the detected air/fuel ratio) in this condition. Then, the determination system determines whether the air/fuel ratio sensor is adequate for making a cylinder-to-cylinder A/F imbalance determination, by comparing the evaluation parameter with a reference parameter (an evaluation parameter obtained based on output values of a reference air/fuel ratio sensor in the same forced imbalance condition). | 03-03-2011 |
| 20110126517 | CATALYST DETERIORATION DIAGNOSIS SYSTEM AND METHOD FOR INTERNAL COMBUSTION ENGINE - A catalyst deterioration diagnosis system performs a diagnosis of deterioration of the oxidation catalyst based on a high-temperature-inflow-condition exhaust gas temperature and a low-temperature-inflow-condition exhaust gas temperature. The high-temperature-inflow-condition exhaust gas temperature is a temperature detected by a temperature sensor while the temperature of the exhaust gas that flows into the oxidation catalyst is in a high temperature region H while the reducing agent is supplied from the reducing agent supply means into the exhaust gas that flows into the oxidation catalyst. The low-temperature-inflow-condition exhaust gas temperature is a temperature detected by the temperature sensor while the temperature of the exhaust gas that flows into the oxidation catalyst is in a low temperature region L while the reducing agent is supplied from a reducing agent supply means into the exhaust gas that flows into the oxidation catalyst. | 06-02-2011 |
