Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An air-fuel ratio sensor includes a sensor element inserted through a cylindrical housing for detecting an air-fuel ratio in an atmosphere of unburnt gas, and a measured gas side cover disposed on an end of the cylindrical housing so as to cover the sensor element and defining an inside chamber for storing therein a gas to be measured. The cover has a nested structure composed of a plurality of cup-shaped cover members disposed one inside another, each cover member having a gas inlet hole formed in a side wall thereof and a bottom hole formed in a bottom wall thereof. The gas inlet hole of an innermost one of the plural cover members that directly faces the sensor element is offset from an air-fuel ratio detecting portion of the sensor element toward the housing in an axial direction of the sensor.

Abstract: An air-fuel ratio sensor includes a sensor element inserted through a cylindrical housing for detecting an air-fuel ratio in an atmosphere of unburnt gas, and a measured gas side cover disposed on an end of the cylindrical housing so as to cover the sensor element and defining an inside chamber for storing therein a gas to be measured. The cover has a nested structure composed of a plurality of cup-shaped cover members disposed one inside another, each cover member having a gas inlet hole formed in a side wall thereof and a bottom hole formed in a bottom wall thereof. The gas inlet hole of an innermost one of the plural cover members that directly faces the sensor element is offset from an air-fuel ratio detecting portion of the sensor element toward the housing in an axial direction of the sensor.

Abstract: Air fuel ratio sensor for use in an exhaust gas purification system for an internal combustion engine. The sensor has an outer and inner cover 12 and 13 for protection of lead wires 16, 18 and 19 to a detecting element 3 and a heater 5 of the sensor, a rubber seal for 2 for obtaining a sealing between the covers and the lead wires and a water repellent filter 36 for obtaining a seal between the inner and outer covers 12 and 13, while keeping an air ventilation capability of the space inside the covers. For receiving the lead wires 16, 18 and 19, the seal 2 is formed with holes 20 such that the minimum thickness between the holes and the minimum thickness between the hole and an outer surface of the seal is 1 mm or more. A crimping of the outer cover 12 is done so that a deformation of the seal 2 in a range between 10 to 20% of the outer diameter is obtained.

Abstract: A gas concentration detecting device for detecting the concentration of a component, such as an oxygen in an exhaust gas of an internal combustion engine. The device has a concentration detecting body 2 for detecting the oxygen and a cover 3 of a double wall structure which is for encircling the portion of the detecting body opened to the flow of the exhaust gas to be detected. The cover 3 has, at its axial tip end wall, a plurality of holes 33 and 34 arranged in such a manner that one of the holes functions as a gas inlet hole and the other hole functions as a gas outlet hole in order to cause the gas to be smoothly ventilated. The cover has, at its side, a wall of a closed structure with no hole for the passage of the gas, which is effective for preventing the cover 3 and the detecting body 2 from being cooled by the exhaust gas, thereby enhancing a heat retaining capacity, thereby preventing particulates from being deposited.

Abstract: An oxygen concentration detector easily assembled without producing conducting malfunctions at an external electrode includes a cylindrical housing and a detecting element being inserted into and disposed inside the housing. Powdery seal materials made of ceramic power are filled under pressure between a top portion of the detecting element and the housing. The detecting element has the external electrode at an external surface thereof and a lead portion extending upwardly from the external electrode. A ring-shaped conducting member is installed between the lead portion of the detecting element and the housing as a ground to conduct electricity therebetween and has a resilient contacting piece in contact with the lead portion at an inner peripheral portion of the ring-shaped conducting member.

Abstract: Air fuel ratio sensor for use in an exhaust gas purification system for an internal combustion engine. The sensor has an outer and inner cover 12 and 13 for protection of lead wires 16, 18 and 19 to a detecting element 3 and a heater 5 of the sensor, a rubber seal for 2 for obtaining a sealing between the covers and the lead wires and a water repellent filter 36 for obtaining a seal between the inner and outer covers 12 and 13, while keeping an air ventilation capability of the space inside the covers. For receiving the lead wires 16, 18 and 19, the seal 2 is formed with holes 20such that the minimum thickness between the holes and the minimum thickness between the hole and an outer surface of the seal is 1 mm or more. A crimping of the outer cover 12 is done so that a deformation of the seal 2 in a range between 10 to 20% of the outer diameter is obtained.

Abstract: A laminated type oxygen concentration sensor includes a laminated type oxygen concentration sensor element having a plate shape with a flange on a side surface thereof, and a housing in a tubular shape having an inclination seat inclined in a central axial direction thereof. The housing supports the laminated type oxygen concentration sensor element by contacting the inclination seat with the flange of the laminated type oxygen concentration sensor element at an outer circumference of the inclination seat. Since the sensor element is supported by contacting the flange with the inclination seat of the housing at the outer circumference of the inclination seat, the pressure per unit area imposed on the sensor element is minimized and cracking of the sensor element is prevented.