Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Nippon Soken, Inc.

Denso Corpora Tion

Masato Katsuno

Takashi Araki

Manabu Yoshidome

Masahiro Yamamoto

Masayuki Tamura

Go Miyagawa

Toshihiro Sakawa

Eiji Takemoto

Tatsuya Fujita

Hiroshi Haraguchi

Kunio Nanba

Akio Matsunaga

Yoshinori Nakayama

Masato Minato

An exhaust gas sensor includes an element cover, a heater, a heater control section, and a cover state diagnosing section. The element cover accommodates a sensor element including a detection section and includes one or more gas flow holes. The heater heats the sensor element. The heater control section controls how the heater heats the sensor element. The cover state diagnosing section diagnoses a state of the element cover using heater information obtained when the heater is operated by the heater control section. The cover state diagnosing section includes a diagnosability determining section, which determines whether the state of the element cover is diagnosable based on an accuracy of the heater information obtained from an operating state of the heater and a surrounding environmental state of the element cover.

Exhaust gas sensor

A particulate matter detecting apparatus (S) comprises a sensor body (S) which has a sensor device () which is retained in a housing (H) secured to an exhaust pipe () of an internal combustion engine (ENG) and detects particulate matter contained in exhaust gas, a sensor temperature determining unit () which works to determine a temperature of the sensor device, and a mounted condition diagnosis unit () which diagnoses a mounted condition where the sensor body is mounted in the exhaust pipe. The mounted condition diagnosis unit includes a diagnosis threshold setting unit () and a mount error determining unit (). The diagnosis threshold setting unit determines a diagnosis threshold (Tth), as used in a diagnosis of the mounted condition, as a function of an operating condition of the internal combustion engine to have a temperature value lower than a temperature of the sensor device when the sensor body is normally mounted in the exhaust pipe. When a sensor temperature (T), as determined by the sensor temperature determining unit, is lower than the diagnosis threshold, the mount error determining unit determines that an error in the mounted condition is occurring.

Particulate matter detecting apparatus capable of mounted condition diagnosis

An exhaust gas sensor that detects a specific component included in an exhaust gas includes a sensor element including a detector, an element cover that accommodates the sensor element and has a gas ventilation hole, a heater that heats the sensor element, a heater control section, and an installation state diagnosis section that diagnoses a state of an element cover based on a sensor temperature detected by a sensor temperature detection section. The installation state diagnosis section includes a temperature variation amount calculation section that calculates a sensor temperature variation amount, a temperature variation amount integration section that sums the sensor temperature variation amounts, and an abnormality determination section that determines presence or absence of an abnormal installation based on a comparison result between variation amount integration information of the sensor temperature and a diagnosis threshold value.

After an engine is started, an ECU performs first regeneration processing of a PM sensor through heating by a heater and, after the first regeneration processing, applies a voltage continuously to detection electrodes for a predetermined voltage application period. The ECU causes PM to adhere to an insulating substrate due to the voltage application and, at a time point after the predetermined time period has elapsed, determines the amount of PM that is adhering to the insulating substrate. When a predetermined condition is satisfied outside the voltage application period, the ECU determines whether the amount of adhering PM on the insulating substrate is equal to or greater than an excess determination threshold value. If the amount of adhering PM is determined to be equal to or greater than the excess determination threshold value, the ECU performs second regeneration processing of the PM sensor, through heating by the heater.

Sensor control apparatus

An apparatus which detects particulate matter is provided. This apparatus estimates a volume of water inside an exhaust passage using estimation sections. When an estimated volume of water is larger than a water drainage threshold, an element portion is heated using a heater by the first temperature range controller, in a temperature range which resists water-induced cracking independent of a volume of water droplets. If the estimated volume of water is less than a water drainage threshold, the water drainage determination section determines that the water drainage of the exhaust passage is completed. Additionally, if it is estimated that the water drainage is completed, the element portion is heated by a second temperature controller at temperature lower than a starting temperature of combustion of particulate matter and in order to repel water adhered onto the element portion in a water-repellent temperature range for a predetermined period.

Particulate matter detection apparatus that mitigates water collection

A particulate matter detecting device includes: an element unit on which particulate matter contained in exhaust gas from an internal combustion engine is deposited; a heater that heats the element unit; a detecting unit that detects the amount of particulate matter on the basis of electrical characteristics of the element unit; and a control unit that controls the operation of the heater. For a predetermined period that does not include a period in which the particulate matter is deposited on the element unit, the control unit operates the heater using a predetermined amount of control set in advance such that the temperature of the element unit is higher than the temperature of the exhaust gas and lower than a predetermined temperature at which the element unit is thermally degraded.

Particulate matter detecting device

A particulate matter detection apparatus is provided with an element portion onto which PM contained in exhaust gas of an engine adheres thereto. A heater which heats the element portion, a quantity detecting portion which detects a quantity of the PM based on electrical properties of the element portion and a temperature detecting portion which detects a temperature of the element portion. The apparatus is further provided with a first and second temperature controller. The first temperature controller heats the element portion using a heater in a first period, which excludes a period in which PM adheres to the element portion based on a detected temperature of the element portion. The element portion is heated in a first temperature range to combust soluble organic fractions contained in the PM and resist melting of ash components contained in the PM. The first period excludes a period in which PM adheres to the element portion. The second temperature controller heats the element portion in the second temperature range, which is higher than the first temperature range using the heater, such that ash is combusted, based on a detected temperature of the element portion.

Particulate matter detection apparatus

A filter fault detection apparatus for a filter mounted on an exhaust passage of an internal combustion engine for collecting particulate matter includes a sensor mounted on the exhaust passage downstream of the filter. The sensor includes an insulative sensor element formed with a pair of electrodes on which particulate matter is collected, the sensor generating a sensor output corresponding to an amount of particulate matter collected on the sensor element when the electrodes become electrically conductive therebetween, causing the sensor output to rise. The apparatus further includes an acquiring unit that acquires, as an output variation, a temporal variation of the sensor output after rise of the sensor output, and a fault determination unit that performs a fault detection process for detecting presence of a fault in the filter based on the output variation of the sensor output to determine whether the filter is normal or faulty.

Filter fault detection apparatus

In a system, an actuator is linked to a valve rotatably installed in a passage through which gas flows. The actuator changes torque to be applied to the valve so as to adjust a rotational position of the valve based on a deviation between a current position and a target position. In the system, a first storing unit stores therein a first threshold. The first threshold is defined in a variation range within which a torque parameter is variable depending on change in the torque to be applied to the valve. The first threshold allows whether there is a possibility that an operation of the actuator is unstable. If the torque parameter substantially shifts either to or through the first threshold in the variation range, a restricting unit restricts variation in the torque parameter with the gas-flow being substantially kept through the passage.

Method and system for controlling an actuator to rotate a valve

A valve control device corrects a change rate of an opening degree of a valve in accordance with engine rotation speed when deposit elimination operation is performed. The valve control device corrects an inclination between a positive maximum opening degree and a negative maximum opening degree of the valve in accordance with the engine rotation speed when the deposit elimination operation is performed. Thus, when the engine rotation speed is low and a noise accompanying the deposit elimination operation becomes more audible, the change rate of the opening degree of the valve is reduced. As a result, the noise accompanying the deposit elimination operation is reduced and annoyance for vehicle occupants is reduced.

Valve control device reducing noise

An EGR-gas temperature estimation apparatus for an internal combustion engine which has an exhaust circulation pipe and an EGR-gas cooling apparatus. The estimation apparatus obtains the cooling efficiency &#x3b7;egr of the EGR-gas cooling apparatus from the temperature Tex of EGR gas at the inlet of the exhaust circulation pipe and the flow rate Gegr of the EGR gas, and obtains the temperature THW of engine cooling water, used as a coolant for the EGR-gas cooling apparatus. Subsequently, the estimation apparatus calculates the temperature Tegr of the EGR gas at the outlet of the exhaust circulation pipe by the expression Tegr=Tex&#x2212;&#x3b7;egr&#xb7;(Tex&#x2212;THW). Since the cooling efficiency &#x3b7;egr greatly changes depending on the EGR-gas flow rate Gegr and the EGR-gas temperature Tex, the estimation apparatus can accurately estimate the cooling efficiency &#x3b7;egr, and therefore can accurately estimate the EGR-gas temperature Tegr.

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Kariya, Japan

Masato Katsuno