Denso Corporation

Denso Corpora Tion

Kensuke Takizawa

Kazuhiko Koike

Go Miyagawa

Toshihiko Harada

Satoshi Nakamura

Tomohiko Nakanishi

Masayuki Tamura

Manabu Yoshidome

Hironobu Shimokawa

Hiroki Ichikawa

Yoichi Kadota

Hiroaki Yoto

Eriko Maeda

A deterioration determination apparatus is usable with an ammonia sensor that includes an ammonia element portion that includes, a solid electrolyte, an ammonia electrode, and a reference electrode. The deterioration determining apparatus compares a first evaluation value and a second evaluation value, and determines whether deterioration has occurred in the ammonia element portion of the ammonia sensor at an evaluation time or subsequent to the evaluation time. The first evaluation value is based on a first sensor current obtained when a DC voltage is applied between the ammonia electrode and the reference electrode of the ammonia element portion at an initial time that is during an initial use period of the ammonia sensor. The second evaluation value is based on a second sensor current obtained when the DC voltage is applied between the ammonia electrode and the reference electrode subsequent to the initial period of use of the ammonia sensor.

Deterioration determination apparatus for ammonia sensor

An abnormality determination apparatus for an ammonia sensor is usable in an exhaust purification system including a catalyst, a supply apparatus, an ammonia sensor, an NOsensor, and an oxygen sensor. During a continuation period within which ammonia supply to the catalyst continues after the supply apparatus stops supply of reductant, the abnormality determination apparatus calculates the ammonia concentration on a downstream side of the catalyst as a first concentration value, based on an output of the ammonia sensor and an output of the oxygen sensor. During the continuation period, the abnormality determination apparatus calculates the ammonia concentration on the downstream side of the catalyst as a second concentration value, based on an output of the NOsensor and the output of the oxygen sensor. The abnormality determination apparatus determines presence or absence of abnormality in the ammonia sensor based on the first concentration value and the second concentration value.

Abnormality determination apparatus for ammonia sensor

Failure detection apparatus for a particulate filter includes: a sensor having a particulate matter detection unit that outputs a signal corresponding to the amount of accumulated PM, and a heater unit that heats the particulate matter detection unit; a regeneration control unit that causes the heater unit to heat the particulate matter detection unit to a regeneration temperature allowing the particulate matter to be burned off; a start detection unit that determines the start of the internal combustion engine; failure determination unit that determines whether exhaust gas contains water droplets while the engine is in operation; a heating control unit that causes the heater unit to heat the particulate matter detection unit to a first temperature allowing the accumulated particulate matter to remain and the moisture included in the particulate matter to be removed; and failure determination unit that determines whether the filter has failure based on a sensor output value.

Failure detection apparatus and failure detection method for particulate filter

A failure detection device has a PM filter, a PM detection sensor having a sensor element arranged at a downstream of the PM filter, an ECU and a PM detection sensor control part. The sensor element detects an amount of PM in exhaust gas, and generates a sensor signal corresponding to the detected PM amount. A load detection part in the ECU detects an engine load. A judgment execution determination part in the control part compares the detected engine load with a threshold value, and determines whether a PM filter failure detection should be performed based on the comparison result. A failure judgment part compares the sensor signal with a failure judgment threshold value when the determination part decides that it is necessary to perform the failure detection of the PM filter, and determines that the PM filter failure has occurred based on the latter comparison result.

Failure detection device for particulate matter filter and method of detecting failure of particulate matter filter

A control unit () estimates an output value of a PM sensor (S) located at a downstream side of a DPF used as a reference filter, and detects whether the estimated output value exceeds a predetermined value (S). When the estimated output value exceeds the predetermined value (YES in S), the control unit detects an output value of the PM sensor (S), and a heater heats the PM sensor (S). The control unit detects an output value of the PM sensor (S) after the PM sensor is heated, and calculates a change ratio of the output values of the PM sensor before and after heating (S). The control unit estimates an average particle size of PM based on the calculated change ratio (S), and detects whether the DPF has failed based on a comparison result of a corrected output value of the PM sensor with a threshold value.

Filter failure detection device and particulate matter detection device

A porous honeycomb structure including multiple co-catalyst particles and multiple inorganic binder particles of smaller particle diameter than the co-catalyst particles. Each co-catalyst particle is comprised of a ceria-zirconia solid solution. The inorganic binder particles reside between the co-catalyst particles. In the honeycomb structure, an exposure fraction of the co-catalyst particles from the inorganic binder particles on a cross-section of the honeycomb structure is within a range of 3 to 10%.

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Nisshin, Japan

Kensuke Takizawa