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Keiichiro Aoki

Keiichiro Aoki, Shizuoka-Ken JP

Patent application numberDescriptionPublished
20090288391CATALYST DETERIORATION DETECTION DEVICE - The present invention detects the deterioration of a catalyst. In accordance with an output from an oxygen sensor, a catalyst deterioration detection device for the catalyst positioned in an exhaust path of an internal combustion engine detects a maximum oxygen storage state where an exhaust gas outflowing downstream of the catalyst contains excess oxygen and a minimum oxygen storage state where the exhaust gas outflowing downstream of the catalyst lacks oxygen. Control is exercised to provide a rich target air-fuel ratio for the internal combustion engine during an oxygen release period between the instant at which the maximum oxygen storage state is detected and the instant at which the minimum oxygen storage state is detected later, and to provide a lean target air-fuel ratio for the internal combustion engine during an oxygen storage period between the instant at which the minimum oxygen storage state is detected and the instant at which the maximum oxygen storage state is detected later. Further, the amount of oxygen released from the catalyst during the oxygen release period or the amount of oxygen stored by the catalyst during the oxygen storage period is detected as an oxygen storage amount. The deterioration of the catalyst is then judged in accordance with the oxygen storage amount. Moreover, when exercising control for catalyst deterioration detection, the catalyst deterioration detection device sets up oxygen storage amount detection conditions for correcting a variation that may occur in the oxygen release period or the oxygen storage period depending on a difference in output detection conditions for the oxygen sensor.11-26-2009
20100000984HEATER CONTROL DEVICE AND METHOD FOR EXHAUST GAS SENSOR - An oxygen concentration sensor is disposed in an engine exhaust passageway. The alcohol concentration in the fuel used in the internal combustion engine is detected. A target impedance is set on the basis of the detected alcohol concentration. The actual impedance of a sensor element of the oxygen concentration sensor is detected. The heater output of the exhaust gas sensor is controlled so that the actual impedance becomes equal to the target impedance, whereby the temperature of the sensor element represented by the impedance becomes equal to a target temperature represented by the target impedance.01-07-2010
20100191444HYDROGEN DETECTING DEVICE AND METHOD, AND INTERNAL COMBUSTION ENGINE ABNORMALITY DECIDING DEVICE - A device, which detects information about a hydrogen concentration level, includes an air-fuel ratio sensor, an air-fuel ratio controller, and a detecting portion. The detecting portion calculates either a ratio of response periods or a difference between the response periods to detect the hydrogen concentration level. One of the response periods is a period from the time the air-fuel ratio controller switches the target air-fuel ratio from rich to lean to the time the air-fuel ratio sensor detects this. The other of the response periods is a period from the time the air-fuel ratio controller switches the target air-fuel ratio from lean to rich to the time the air-fuel ratio sensor detects this. This allows the decisions of a variation between cylinders and an exhaust purifying catalyst degradation.07-29-2010
20100300382FUEL REFORMING APPARATUS - Fuel reforming catalysts 12-02-2010
20100300418AIR-FUEL RATIO SENSOR AND CONTROL APPARATUS FOR INTERNAL COMBUSTION ENGINE - There is provided an air-fuel ratio sensor with which an improvement in the accuracy in detecting the air-fuel ratio of detection target gas and an improvement in the response characteristics can both be achieved. The sensor includes a sensor element that outputs an output signal indicative of the air-fuel ratio of a detection target gas, a pair of electrodes including a detection target gas side electrode to which the detection target gas is introduced and an atmosphere side electrode exposed to the atmosphere, which are arranged in such a way as to sandwich the sensor element, a diffusion-controlling layer that is disposed on the sensor element in such a way as to cover the detection target gas side electrode and introduces the detection target gas from an entrance portion through which the detection target gas flows in to the detection target gas side electrode, and a catalyst layer provided on a part of the entrance portion.12-02-2010
20110067481EXHAUST GAS SENSOR - An exhaust gas sensor that simultaneously exhibits enhanced water soak resistance and functionality, that is multilayered and exposed to a space in an exhaust path. The exhaust gas sensor includes: an electrolyte layer, positioned between an exhaust electrode and an atmosphere electrode; an atmospheric layer formation layer formed toward the atmosphere electrode to form an atmospheric layer to which the atmosphere electrode is exposed; a porous diffusion resistance layer formed toward the exhaust electrode to control flow rate of an exhaust gas reaching the exhaust electrode; and a porous trap layer formed to cover the entire section exposed to the space in the exhaust path. The trap layer includes a first trap layer, which covers a region near a gas inlet/outlet section of the diffusion resistance layer, and a second trap layer, which covers another region that covered by the first trap layer. The first trap layer is thinner than the second trap layer.03-24-2011

Patent applications by Keiichiro Aoki, Shizuoka-Ken JP

Keiichiro Aoki, Numazu-Shi JP

Patent application numberDescriptionPublished
20090019834CATALYST DETERIORATION DEGREE ACQUIRING APPARATUS IN INTERNAL COMBUSTION ENGINE - The apparatus obtains a decreasing gradient of the maximum oxygen storing quantity Cmax with respect to the increase in an air flow rate Ga on the basis of two maximum oxygen storing quantities Cmax, which are respectively estimated in case where the air flow rate Ga assumes two different values, and the two values of the air flow rate Ga. As the deterioration degree of the catalyst unit 01-22-2009
20090037079Air-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
20100229628GAS CONCENTRATION DETECTION DEVICE - A gas concentration detection device includes: a first sensor having a resistance layer exposed to a gas, and an electrode covered by the resistance layer, the first sensor producing an output according to a gas component ratio on the electrode surface; and a second sensor having a pump cell that pumps oxygen into a gas chamber that contains part of the gas or discharges oxygen out of the gas chamber, and a sensor cell that produces an output according to a gas component ratio in the gas within the gas chamber, the second sensor producing an output based on the pump cell current when the pump cell is operated such that the output of the sensor cell is a predetermined value; and a hydrogen concentration detection unit that detects a hydrogen concentration in the gas based on an output difference between the first sensor output and the second sensor output.09-16-2010

Patent applications by Keiichiro Aoki, Numazu-Shi JP

Keiichiro Aoki, Sunto-Gun JP

Patent application numberDescriptionPublished
20100199636EXHAUST PURIFYING APPARATUS FOR AN INTERNAL COMBUSTION ENGINE - A present exhaust purifying apparatus comprises a SCR catalyst, a urea-water injector, and a downstream air-fuel ratio sensor (an oxygen concentration sensor having a diffusion resistance layer) disposed at a position downstream of the SCR catalyst. The present apparatus, when a predetermined condition is satisfied, stops injecting the urea-water from the urea-water injector, and obtains an output value of the downstream air-fuel ratio sensor, as a first output value, in that state. The present apparatus obtains an output value of the downstream air-fuel ratio sensor when the urea-water is being injected from the urea-water injector, as a second output value. The present apparatus obtains a concentration of ammonia which flows out from the SCR catalyst based on the difference between the first output value and the second output value.08-12-2010
20110155113DEVICE FOR DETERMINING ACTIVATION OF EXHAUST GAS SENSOR AND CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE - The invention has an object to provide a device for determining activation of an exhaust gas sensor which accurately determines a time at which an exhaust gas sensor output is usable, and can suppress an adverse effect caused by use of the exhaust gas sensor output including a large effect of adsorbed species. A time is measured from a time point when a temperature of an air-fuel ratio sensor 06-30-2011

Keiichiro Aoki, Susono-Shi JP

Patent application numberDescriptionPublished
20090050493Gas Sensor, Fuel Supply System Using the Same, and Method of Using Gas Sensor - A gas sensor has a gas diffusion barrier that supports therein a catalyst that catalyzes a reaction between combustible components and oxygen; a solid electrolyte having oxide ion conductivity; and electrodes formed on opposite surfaces of the solid electrolyte. The electrode is formed in a region into which ambient gas diffuses at a rate limited by the gas diffusion barrier. The electrode also catalyzes the reaction between combustible gas and oxygen. The electrode is formed in a region into which atmosphere is introduced.02-26-2009
20090173324Control system for an exhaust gas sensor - An oxygen sensor is mounted in an exhaust path of an internal combustion engine. The status of an exhaust gas is detected in accordance with the output of the oxygen sensor. The oxygen sensor incorporates a heater for heating an element of the sensor. In a region in which the temperature of the sensor element is below 300° C., an adsorbable species becomes adsorbed. In a region in which the exhaust pipe temperature is above 80° C., the adsorbable species becomes adsorbed remarkably. Power supply control is continuously exercised over the heater so as to maintain the sensor element at a temperature of 300° C. or higher until the exhaust pipe temperature drops below 80° C. after an internal combustion engine stop. The power supply to the heater is shut off after the exhaust pipe temperature drops below 80° C.07-09-2009
20090173325Control system for an exhaust gas sensor - An oxygen sensor is mounted in an exhaust path of an internal combustion engine. The status of an exhaust gas is detected in accordance with the output of the oxygen sensor. The oxygen sensor incorporates a heater for heating an element of the sensor. In a region in which the temperature of the sensor element is below 300° C., an adsorbable species becomes adsorbed. In a region in which the exhaust pipe temperature is above 80° C., the adsorbable species becomes adsorbed remarkably. Power supply control is continuously exercised over the heater so as to maintain the sensor element at a temperature of 300° C. or higher until the exhaust pipe temperature drops below 80° C. after an internal combustion engine stop. The power supply to the heater is shut off after the exhaust pipe temperature drops below 80° C.07-09-2009
20090173326Control system for an exhaust gas sensor - An oxygen sensor is mounted in an exhaust path of an internal combustion engine. The status of an exhaust gas is detected in accordance with the output of the oxygen sensor. The oxygen sensor incorporates a heater for heating an element of the sensor. In a region in which the temperature of the sensor element is below 300° C., an adsorbable species becomes adsorbed. In a region in which the exhaust pipe temperature is above 80° C., the adsorbable species becomes adsorbed remarkably. Power supply control is continuously exercised over the heater so as to maintain the sensor element at a temperature of 300° C. or higher until the exhaust pipe temperature drops below 80° C. after an internal combustion engine stop. The power supply to the heater is shut off after the exhaust pipe temperature drops below 80° C.07-09-2009
20090173327Control system for an exhaust gas sensor - An oxygen sensor is mounted in an exhaust path of an internal combustion engine. The status of an exhaust gas is detected in accordance with the output of the oxygen sensor. The oxygen sensor incorporates a heater for heating an element of the sensor. In a region in which the temperature of the sensor element is below 300° C., an adsorbable species becomes adsorbed. In a region in which the exhaust pipe temperature is above 80° C., the adsorbable species becomes adsorbed remarkably. Power supply control is continuously exercised over the heater so as to maintain the sensor element at a temperature of 300° C. or higher until the exhaust pipe temperature drops below 80° C. after an internal combustion engine stop. The power supply to the heater is shut off after the exhaust pipe temperature drops below 80° C.07-09-2009

Keiichiro Aoki, Numazu-City JP

Patent application numberDescriptionPublished
20080246955Method of detecting alcohol concentration and alcohol concentration detecting apparatus - In a detection of an alcohol concentration, a first light and a second light are irradiated to a mixed liquid including a fossil fuel, an alcohol, and water, and the alcohol concentration is calculated based on amounts of the first light and the second light permeated through the mixed liquid. In the detection, a difference of a transmittance of the fossil fuel with respect to the first light and each transmittance of the alcohol and water with respect to the first light is larger than a first value. In addition, a difference of a transmittance of water with respect to the second light and each transmittance of the fossil fuel and the alcohol with respect to the second light is larger than a second value.10-09-2008

Keiichiro Aoki, Sunto-Gun, Shizuoka-Ken JP

Patent application numberDescriptionPublished
20110271665AIR-FUEL RATIO IMBALANCE AMONG CYLINDERS DETERMINING APPARATUS FOR AN INTERNAL COMBUSTION ENGINE - An air-fuel ratio imbalance among cylinders determining apparatus (a determining apparatus) according to an aspect of the present invention, obtains a parameter X for imbalance determination which becomes larger as a variation of an air-fuel ratio of an exhaust gas passing through a position at which the air-fuel ratio sensor is disposed becomes larger, based on an output value Vabyfs of an air-fuel ratio sensor 11-10-2011