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 |
20110191005 | APPARATUS FOR DETECTING ABNORMAL AIR-FUEL RATIO VARIATION AMONG CYLINDERS OF MULTI-CYLINDER INTERNAL COMBUSTION ENGINE - An apparatus for detecting an abnormal air-fuel ratio variation among cylinders of a multi-cylinder internal combustion engine includes: a catalyst that is arranged in an exhaust passage of the multi-cylinder internal combustion engine; a catalyst temperature detecting unit that detects a temperature of the catalyst; and an abnormality detecting unit that detects an abnormal air-fuel ratio variation among the cylinders on the basis of the detected catalyst temperature, wherein the abnormality detecting unit calculates a temperature parameter on the basis of the detected catalyst temperature, and the abnormality detecting unit detects the abnormal air-fuel ratio variation among the cylinders on the basis of the temperature parameter at the time when a predetermined period of time has elapsed after a cold start of the internal combustion engine. | 08-04-2011 |
20110265461 | ABNORMALITY DETECTION APPARATUS FOR EXHAUST GAS PURIFICATION APPARATUS AND ABNORMALITY DETECTION METHOD FOR EXHAUST GAS PURIFICATION APPARATUS - It is determined quickly whether there is a shortage in reducing agent supplied to an NOx selective reduction catalyst. After it is determined that a quantity of reducing agent equal to or larger than a predetermined quantity is absorbed in the NOx selective reduction catalyst on the assumption that there is no abnormality in reducing agent supply unit, the supply of a quantity of reducing agent needed to reduce a quantity of NOx flowing into the NOx selective reduction catalyst is started. A determination of an abnormality in the reducing agent supply unit is made based on the NOx removal rate after the lapse of a predetermined period of time since the start of the supply of reducing agent. The NOx removal rate becomes lower when there is an abnormality in the reducing agent supply unit. | 11-03-2011 |
20110282541 | MONITORING APPARATUS FOR A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE - A monitoring apparatus including a catalytic converter, an upstream air-fuel ratio sensor, and a downstream air-fuel ratio sensor; calculates a sub feedback amount to have an air-fuel ratio represented based on an output value of the downstream air-fuel ratio sensor coincide with a stoichiometric air-fuel ratio; and controls an fuel injection amount based on an output value of the upstream air-fuel ratio sensor and the sub feedback amount, in such a manner that an air-fuel ratio of a mixture supplied to an engine coincides with the stoichiometric air-fuel ratio. | 11-17-2011 |
20110283981 | APPARATUS FOR ACQUIRING RESPONSIBILITY OF OXYGEN CONCENTRATION SENSOR - The fact that “with respect to a process in which the output value of a downstream air-fuel ratio sensor (sensor output value) is inverted from the minimum output value to the maximum output value during execution of an active control, the local maximum and minimum values of the secondary differential value of the sensor output value is widely affected by the size of the response delay of the downstream air-fuel ratio sensor and the size of the degree of the degradation of the three-way catalyst” is utilized. By preliminarily acquiring and memorizing, as maps, these relations obtained through an experiment, and applying the “local maximum and minimum values of the secondary differential value of the sensor output value” calculated from the transition of the sensor output value acquired during execution of the active control to the maps, the response delay (time constant) of the downstream air-fuel ratio sensor is acquired. | 11-24-2011 |
20110288739 | APPARATUS FOR DETERMINING AN AIR-FUEL RATIO IMBALANCE AMONG CYLINDERS OF AN INTERNAL COMBUSTION ENGINE - An apparatus for determining an air-fuel ratio imbalance among cylinders including an upstream air-fuel ratio sensor, a catalytic converter, and a downstream air-fuel ratio sensor disposed at positions downstream of an exhaust gas aggregated portion, calculates a sub feedback amount to have an output value of the downstream air-fuel ratio sensor coincides with a value corresponding to the stoichiometric air-fuel ratio, and performs an air-fuel ratio feedback control to have an air-fuel ratio of a mixture supplied to an engine based on the sub feedback amount and the output value of the upstream air-fuel ratio sensor. | 11-24-2011 |
20110290217 | ENGINE SYSTEM CONTROL DEVICE - The present invention provides an engine system control device to be applied to an engine system provided with an engine having a variable compression ratio mechanism capable of changing a compression ratio. In the case where generation of failure in a compression ratio control system is detected, determination of a state of a member placed in an intake and exhaust system of the engine is inhibited. | 12-01-2011 |
20110314792 | ABNORMALITY DIAGNOSIS SYSTEM AND METHOD FOR DIAGNOSING ABNORMALITY IN FILTER REGENERATION SYSTEM - The invention intends to provide a technology which makes it possible to diagnose with higher accuracy whether or not abnormality occurs in a filter regeneration system causing excessive execution frequency of a regeneration process. The filter regeneration system initiates execution of the regeneration process, incase an estimated particulate matter (PM) accumulation amount at the filter reaches a pre-determined regeneration requiring accumulation amount; or in case the pressure upstream of the filter or the differential pressure across the filter reaches a pre-determined regeneration requiring value, the value being larger than the pressure or the differential pressure corresponding to the regeneration requiring accumulation amount. Then, the diagnosis is carried out based on a ratio of an estimated PM accumulation amount at the initiation of the execution of the regeneration process to the regeneration requiring accumulation amount. | 12-29-2011 |
20120035831 | AIR-FUEL RATIO IMBALANCE AMONG CYLINDERS DETERMINING APPARATUS FOR A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE - A judging device comprises a catalyst, an upstream air/fuel ratio sensor having an air/fuel ratio sensing element covered with a diffusion resistance layer, and a downstream air/fuel ratio sensor. The judging device performs main feedback control to equalize the air/fuel ratio indicated by the output value of the upstream air/fuel ratio sensor to an upstream target air/fuel ratio and sub-feedback control to equalize the output value of the downstream air/fuel ratio sensor to a downstream target value. The judging device acquires “an imbalance judging parameter” which increases with “the increase of the difference between the amount of hydrogen contained in the exhaust gas before the exhaust gas passes through the catalyst and that after the exhaust gas passes through the catalyst” according to the sub-feedback amount. When the imbalance judging parameter is larger than an abnormality judgment threshold, the judging device judges that an air/fuel ratio imbalance among the cylinders has occurred. The judging device does not make judgment on air/fuel ratio imbalance among the cylinders if a predetermined judgment prohibition condition is satisfied, for example, if the flow of the exhaust gas is a predetermined value or more. | 02-09-2012 |
20120095664 | MALFUNCTION DETECTION APPARATUS AND MALFUNCTION DETECTION METHOD FOR AN EGR SYSTEM - A determination is made more simply as to a malfunction of a low pressure EGR device that supplies an EGR gas from a low pressure EGR passage connecting between an exhaust passage at a location downstream of a turbine and an intake passage. Provision is made for a high pressure EGR device that connects between the exhaust passage at a location upstream of the turbine and the intake passage, the low pressure EGR device that connects between the exhaust passage at a location downstream of the turbine and the intake passage, and a detection unit that detects a malfunction of the low pressure EGR device from the degree of opening of a high pressure EGR valve at the time when the EGR gas is supplied from both the high pressure EGR device and the low pressure EGR device, and at the time when the high pressure EGR valve of the high pressure EGR device is controlled in a feedback manner so as to direct an amount of EGR gas in a cylinder toward a target range of the amount of EGR gas, while carrying out open loop control of a low pressure EGR valve of the low pressure EGR device. | 04-19-2012 |
20120116651 | INTER-CYLINDER AIR-FUEL RATIO IMBALANCE JUDGMENT DEVICE FOR MULTI-CYLINDER INTERNAL COMBUSTION ENGINE - When the intake air amount is smaller than the specific intake air amount, the unit air-fuel ratio change amount calculated during the engine operation is corrected such that the unit air-fuel ratio change amount increases in the condition that the base unit air-fuel ratio change amount is an upper limit and when the intake air amount is greater than the specific intake air amount, the unit air-fuel ratio change amount calculated during the engine operation is corrected such that the unit air-fuel ratio change amount decreases in the condition that the base unit air-fuel ratio change amount is a lower limit. When the corrected unit air-fuel ratio change amount is greater than the judgment value, it is judged that the inter-cylinder air-fuel ratio imbalance condition occurs. | 05-10-2012 |
20120160022 | APPARATUS FOR DETERMINING AN AIR-FUEL RATIO IMBALANCE AMONG CYLINDERS OF AN INTERNAL COMBUSTION ENGINE - An air-fuel ratio imbalance among cylinders determining apparatus according to the present invention is applied to a multi-cylinder internal combustion engine in which a compression ratio is variable. The determining apparatus obtains, using at least an output value of an upstream air-fuel ratio sensor disposed for a catalyst, an “imbalance determining parameter” which becomes larger as a degree of an imbalance among “individual cylinder air-fuel ratios” becomes larger, each of the individual cylinder air-fuel ratios being an air-fuel ratio of a mixture supplied to each of cylinders. Further, the determining apparatus determines that an air-fuel ratio imbalance state among cylinders is occurring, when the imbalance determining parameter is larger than a predetermined threshold. The determining apparatus changes the predetermined threshold in accordance with a mechanical compression ratio of the engine. | 06-28-2012 |
20120173115 | AIR-FUEL RATIO IMBALANCE AMONG CYLINDERS DETERMINING APPARATUS FOR AN INTERNAL COMBUSTION ENGINE - An air-fuel ratio imbalance among cylinders determining apparatus according to the present invention comprises an air-fuel ratio sensor having a protective cover and an air-fuel ratio detection element accommodated in the protective cover, and imbalance determining means. The imbalance determining means obtains a detected air-fuel ratio abyfs based on an output Vabyfs of the air-fuel ratio sensor every elapse of a constant sampling time ts, and obtains, as an indicating amount of air-fuel ratio change rate, a difference (detected air-fuel ratio change rate ΔAF) between a present detected air-fuel ratio abyfs which is newly detected and a previous air-fuel ratio abyfsold which was detected the sampling time ts ago, an average of the detected air-fuel ratio change rate ΔAF, and the like. The imbalance determining means determines that the air-fuel ratio imbalance among cylinders state is occurring, when a magnitude of the indicating amount of air-fuel ratio change rate is larger than an imbalance determination threshold. | 07-05-2012 |
20120173116 | AIR-FUEL RATIO IMBALANCE DETERMINING APPARATUS AMONG CYLINDERS FOR AN INTERNAL COMBUSTION ENGINE - An air-fuel ratio imbalance among cylinders determining apparatus according to the present invention obtains an output Vabyfs of an air-fuel ratio sensor disposed at a portion downstream of an exhaust gas aggregated portion of an exhaust gas passage, and obtains a second-order differential value d2AF (a change rate of a change rate of a detected air-fuel ratio abyfs) of a detected air-fuel ratio abyfs represented by the air-fuel ratio sensor output Vabyfs. The imbalance determining apparatus determines that an air-fuel ratio imbalance state among cylinders is occurring when a detected air-fuel ratio second-order differential corresponding value (for example, a second-order differential value d2AF per se) obtained in accordance with the second-order differential value d2AF is larger than a first threshold value. | 07-05-2012 |
20120174900 | APPARATUS AND METHOD FOR DETECTING VARIATION ABNORMALITY IN AIR-FUEL RATIO BETWEEN CYLINDERS - According to a first aspect of the present invention, there is provided an apparatus for detecting variation abnormality in an air-fuel ratio between cylinders comprising a wide-range air-fuel ratio sensor and an O | 07-12-2012 |
20120215427 | INTER-CYLINDER AIR-FUEL RATIO IMBALANCE DETERMINATION APPARATUS FOR INTERNAL COMBUSTION ENGINE - An inter-cylinder air-fuel ratio imbalance determination apparatus (determination apparatus) according to the present invention obtains, as an “EGR supplying state imbalance determination parameter”, a value corresponding to a differential value d(abyfs)dt of a detected air-fuel ratio abyfs represented by an output value of an air-fuel ratio sensor when an EGR gas is being supplied, and obtains, as an “EGR stop state imbalance determination parameter”, a value corresponding to a differential value d(abyfs)dt when an EGR gas supply is being stopped. The determination apparatus obtains an “EGR-causing imbalance determination parameter Pegr” by subtracting the EGR stop state imbalance determination parameter Poff from the EGR supplying state imbalance determination parameter Pon, and determines that an inter-cylinder air-fuel ratio imbalance state has occurred due to the supply of the EGR gas when the parameter Pegr is larger than a threshold Pegrth. | 08-23-2012 |
20120277980 | INTER-CYLINDER AIR-FUEL RATIO IMBALANCE DETERMINATION APPARATUS FOR INTERNAL COMBUSTION ENGINE - An inter-cylinder air-fuel ratio imbalance determination apparatus that obtains, based on an output value Vabyfs of an air-fuel ratio sensor, an air-fuel ratio fluctuation indicating amount (AFD) which becomes larger as an air-fuel ratio fluctuation of an exhaust gas passing through a position at which the air-fuel ratio sensor is disposed becomes larger, during a parameter obtaining period. The determination apparatus estimates an air-fuel ratio sensor element temperature (Temps) having a strong relation with responsiveness of the air-fuel ratio sensor during the parameter obtaining period, and obtains a corrected air-fuel ratio fluctuation indicating amount by correcting the AFD based on the estimated Temps. The determination apparatus adopts the corrected air-fuel ratio fluctuation indicating amount as the imbalance determination parameter X, and determines whether or not an inter-cylinder air-fuel-ratio imbalance state has been occurring based on a comparison between the imbalance determination parameter X and the imbalance determination threshold Xth. | 11-01-2012 |
20120323466 | INTER-CYLINDER AIR-FUEL RATIO IMBALANCE DETERMINATION APPARATUS FOR INTERNAL COMBUSTION ENGINE - An inter-cylinder air-fuel ratio imbalance determination apparatus (determination apparatus) according to the present invention obtains, based on the output value of the air-fuel ratio sensor, an imbalance determination parameter which becomes larger as an air-fuel ratio fluctuation of an exhaust gas passing through a position at which the air-fuel ratio sensor is disposed becomes larger, during a parameter obtaining period. The determination apparatus energizes the heater of the air-fuel ratio sensor in such a manner that a temperature of the air-fuel ratio element during the parameter obtaining period is higher than a temperature of the air-fuel ratio element during a period other than the parameter obtaining period. Accordingly, the imbalance determination parameter is obtained while the responsiveness of the air-fuel ratio sensor is high, and thus, the inter-cylinder air-fuel-ratio imbalance determination having a high accuracy can be made. | 12-20-2012 |
20130014641 | FAILURE DETECTION APPARATUS AND FAILURE DETECTION METHOD FOR A PARTICULATE FILTERAANM Takaoka; KazuyaAACI Susono-shiAACO JPAAGP Takaoka; Kazuya Susono-shi JPAANM Shibata; DaisukeAACI Numazu-shiAACO JPAAGP Shibata; Daisuke Numazu-shi JPAANM Sawada; HiroshiAACI Gotenba-shiAACO JPAAGP Sawada; Hiroshi Gotenba-shi JPAANM Kidokoro; ToruAACI Hadano-shiAACO JPAAGP Kidokoro; Toru Hadano-shi JP - The present invention is intended to detect a failure of a PM filter with a higher degree of accuracy. The present invention is provided with: a PM trapping efficiency calculation part to calculate a PM trapping efficiency (which is a proportion of an amount of particulate matter trapped with respect to an amount of inflow particulate matter) based on an amount of inflow particulate matter obtained by an inflow particulate matter obtaining part, and an amount of outflow particulate matter detected by a PM sensor; and a failure detection part to make a determination that a failure has occurred in the PM filter, in cases where there has appeared a tendency for the PM trapping efficiency to decrease during a period of time until the execution of the following filter regeneration processing is started after the completion of execution of the filter regeneration processing. | 01-17-2013 |
20130098146 | CATALYST DETERIORATION DETECTION APPARATUS AND CATALYST DETERIORATION DETECTION METHOD FOR INTERNAL COMBUSTION ENGINE - Provision is made for a catalyst that is arranged in an exhaust passage of an internal combustion engine and has an oxidation function, downstream side temperature detection means that detects the temperature of an exhaust gas at a downstream side from the catalyst, and addition means that adds a reducing agent into the exhaust gas from an upstream side from the catalyst, wherein there are also provided correlation value calculation means that calculates a correlation value which is correlated with an amount of change of the temperature detected by the downstream side temperature detection means when the reducing agent is added by the addition means and when a transient operation of the internal combustion engine is carried out, and determination means that determines a deterioration of the catalyst by making a comparison between the correlation value and a threshold value which indicates the deterioration of the catalyst. | 04-25-2013 |
20130192208 | FILTER FAILURE DETECTION APPARATUS OF AN INTERNAL COMBUSTION ENGINE - A failure of a filter is detected with a higher degree of accuracy. There are provided a filter that is arranged on an exhaust passage of an internal combustion engine for collecting a substance contained in an exhaust gas, a substance amount detection part that is arranged on the exhaust passage at a downstream side of the filter for detecting an amount of substance in the exhaust gas, a flow speed detection part that detects or estimates a flow speed of the exhaust gas which passes through the filter, and a determination part that makes a determination that the filter is in a failure, when the higher the flow speed of the exhaust gas passing through the filter, the larger a ratio of an amount of change in the amount of substance to an amount of change in the flow speed of the exhaust gas becomes. | 08-01-2013 |
20130216436 | CATALYST DETERIORATION JUDGING SYSTEM - The deterioration judgment for an absorption reduction type NOx catalyst is performed quickly and correctly. A catalyst deterioration judging system includes a supply unit which supplies a reducing agent, a measuring unit which measures a NOx concentration in an exhaust gas at a position downstream from the catalyst, a control unit which regulates an amount of the reducing agent so that an air-fuel ratio of the exhaust gas is a lean air-fuel ratio when the reducing agent is supplied from the supply unit, and a judging unit which judges deterioration of the catalyst on the basis of the NOx concentration measured by the measuring unit when the amount of the reducing agent is regulated so that the air-fuel ratio of the exhaust gas is the lean air-fuel ratio when NOx is absorbed by the catalyst. | 08-22-2013 |
20130261934 | APPARATUS FOR DETERMINING AN AIR-FUEL RATIO IMBALANCE AMONG CYLINDERS OF AN INTERNAL COMBUSTION ENGINE - An apparatus for determining an air-fuel ratio imbalance among cylinders based on an output value of an air-fuel ratio sensor, an imbalance determination parameter which becomes larger or smaller as a difference among air-fuel ratios becomes larger, and performs determining an air-fuel ratio imbalance among cylinders based on a result of a comparison between the imbalance determination parameter and a imbalance determination threshold. The determining apparatus calculates a purge correction coefficient which compensates for a change in the air-fuel ratio due to an evaporated fuel gas which is generated in a fuel tank, while the evaporated fuel gas is being introduced into an intake passage, and corrects a fuel injection amount with the purge correction coefficient FPG. | 10-03-2013 |
20130330234 | CATALYST DETERIORATION JUDGING SYSTEM - The deterioration judgment for an absorption reduction type NOx catalyst is performed quickly and correctly. A catalyst deterioration judging system includes a judging unit which judges that the absorption reduction type NOx catalyst is deteriorated if a detected value of an NH | 12-12-2013 |
20130336841 | CATALYST DETERIORATION DETERMINATION SYSTEM - The determination of deterioration of a NOx storage reduction catalyst ( | 12-19-2013 |
20140003999 | CATALYST DETERIORATION DETERMINATION SYSTEM | 01-02-2014 |
20140216020 | WARM-UP SYSTEM FOR EXHAUST SYSTEM OF INTERNAL COMBUSTION ENGINE - An object of the invention is to prevent a situation in which failure diagnosis for an exhaust system component in an internal combustion engine cannot be completed from continuing for an unduly long period of time. A warm-up system for an exhaust system of an internal combustion engine according to the invention includes a warm-up control performing unit that performs warm-up control for warming up an exhaust system component upon start-up of the internal combustion engine and a failure diagnosis performing unit that performs failure diagnosis for the exhaust system component after the completion of warm-up of the exhaust system component. If a situation in which the operation of the internal combustion engine is stopped after the start of operation of the internal combustion engine before the completion of the failure diagnosis for the exhaust system component performed by the failure diagnosis performing unit has been repeated for a predetermined period of time, the warm-up control performing unit changes the warm-up control performed upon start-up of the internal combustion engine after the predetermined period of time has elapsed to a control that can raise the temperature of the exhaust system component more quickly than the warm-up control performed during the aforementioned predetermined period. | 08-07-2014 |