Ngk Spark Plug Company, Limited

Keisuke Tashima

Masayuki Motomura

Takeshi Sugiyama

Toshiya Matsuoka

Hitoshi Yokoi

Norimasa Osawa

Hirokazu Murase

Toshiya Matuoka

A particulate sensor () to be attached to a gas flow pipe EP through which a gas to be measured EG containing particulates S flows. The particulate sensor () includes a gas introduction discharge pipe (); a discharge element () including a discharge electrode member () maintained at a discharge potential DV and which electrifies particulates contained in the gas under measurement, and a sealed portion (C) located on a proximal end side GK of an element distal end portion and in which the discharge electrode member is disposed and insulated from the outer surface (CS) thereof; a surrounding member () maintained at a first potential SGND; and an electrically conductive glass seal () which establishes electrical communication between the surrounding member and the pipe (), and is in close contact with the outer surface of the sealed portion of the discharge element to provide gastight sealing.

Particulate sensor and method for manufacturing particulate sensor

A particulate amount determination section of a particulate measurement system corrects a measurement signal or the amount of particulates determined from the measurement signal based on one or a plurality of three operating condition parameters selected from speed of the vehicle, rotational speed of the internal combustion engine and torque of the internal combustion engine.

Particulate measurement system

A particulate sensor includes: an inner metallic member which is maintained at a first potential and which has a gas introduction pipe into which a target gas is introduced; a tubular outer metallic member which surrounds the radially outer circumference of the inner metallic member and which is attached to a gas flow pipe to thereby be maintained at a ground potential; and an insulating spacer which is interposed between the inner metallic member and the outer metallic member so as to electrically insulate them from each other and which has a tubular gas contact portion which is exposed to the interior of the gas flow pipe and comes into contact with the gas under measurement. The insulating spacer has a heater for heating the gas contact portion. The heater includes a heat generation resistor embedded in the insulating spacer.

Particulate sensor

A particulate sensor () includes an ion source () and a reference potential member (). The particulate sensor () detects particulates S contained in a gas under measurement EG by means of ions CP. The ion source () includes a ceramic structure () having a ceramic laminate () and a discharge electrode member (). The discharge electrode member () has an inter-layer portion (A,) embedded between the layers of the ceramic laminate () and an exposed portion (B) extending from the inter-layer portion (A,) to a position outside the ceramic laminate (). The discharge electrode member () generates the gaseous discharge between the reference potential member () and the exposed portion (B) including one or more needle-shaped distal end portions () upon application of a constant DC discharge potential PV

A particulate sensor () which detects particulates S contained in a gas under measurement (EG) flowing within a gas flow pipe (EP) has a space forming portion () and an ion source (). The space forming portion () projects into the gas flow pipe EP and forms an internal space MX. The space forming portion () has an introduction port (I) and a discharge port (O) for discharging from the internal space MX the gas EGI introduced through the introduction port (I). The source () produces ions CP by gaseous discharge. The space forming portion () is configured such that the introduced gas EGI is discharged from the internal space MX through the discharge port (O), the gas under measurement EG is introduced into the internal space MX through the introduction port (I), and the introduced gas EGI is mixed with the ions CP produced by the ion source ().

A particulate detection system () for detecting the amount of particulates S in a gas under measurement EG includes a detection section (), a drive circuit (), and a drive control section (). The detection section includes a first potential member () maintained at a first potential PV, a second potential member () maintained at a second potential PVE, PV, and an insulating member () disposed between the first and second potential members. The system includes insulation test means (, S, S) for testing the degree of insulation between the first and second potential members. The drive control section includes drive permission/prohibition determination means S, Sfor determining, on the basis of the degree of insulation tested by the insulation test means, whether to permit the drive of the detection section by the drive circuit.

Microparticle detection system

A particulate sensor including a sensor unit () having an ion generation section (); an electric charge section () for electrically charging at least portion of particulates S using ions PI; a capture section () for trapping at least portion of the ions PI not used for electrically charging the particulates S; and a sensor ground section () connected to the capture section and having a first floating potential corresponding to the amount of the ions PI trapped by the capture section. The sensor unit can detect the amount of the particulates S in the gas on the basis of the electric potential of the sensor ground section. The sensor ground section is covered with insulating ceramic at that outer portion of the sensor unit which comes into contact with the gas.

Microparticle sensor

A particulate detection system () includes detection section (), compressed air source () which includes compressor () for producing compressed air AK, compressor drive circuit () and control means (). The detection section includes a gas jetting source (). A drive condition for jetting air AR from jetting hole (N) at a first flow rate Qis defined as a first drive condition JK, and a drive condition for jetting the air AR at a second flow rate Qsmaller than the first flow rate Qis defined as a second drive condition JK. The control means includes first instruction means Sfor driving the compressor under the first drive condition JKwhen the quantity of the particulates S is detected, and second instruction means Sfor driving the compressor under the second drive condition JKwhen the quantity of the particulates S is not detected.

A particulate detection system () detects the quantity of particulates S contained in exhaust gas EG discharged from an internal combustion engine ENG and flowing through an exhaust pipe EP. The system () includes a detection section () attached to the exhaust pipe EP; and a drive processing circuit () electrically connected to the detection section (), driving the detection section (), and detecting and processing a signal Is from the detection section. The drive processing circuit () includes drive start delay means (S, S, S, S, S, S, S) for delaying start of the drive of the detection section () until a start condition determined by the drive processing circuit () is satisfied after startup of the internal combustion engine ENG.

Particulate detection system

There is provided a fine particle detection system with a fine particle sensor, a cable and a sensor drive control device. The fine particle sensor has an ion source unit with first and second electrodes, a particle charging unit and inner and outer sensor casings. The cable has a power supply wiring line connected to the second electrode, an inner shield line electrically continuous with the inner sensor casing and an outer shield line electrically continuous with the outer sensor casing. The sensor drive control device has an ion-source power supply circuit, a signal current detection circuit, an inner circuit casing electrically continuous with a first output terminal of the ion-source power supply circuit and surrounding the ion-source power supply circuit and an outer circuit casing connected to the ground potential and shielding the ion-source power supply circuit, the signal current detection circuit and the inner circuit casing.

Fine particle detection system

There is provided a fine particle sensor for detecting fine particles in exhaust gas, including an ion generating unit for generating ions by corona discharge, a charging unit for charging the fine particles by some of the generated ions, an ion trapping unit for trapping a remainder of the generated ions and a casing for accommodating therein the charging unit and the ion trapping unit in a given arrangement direction. The casing has a gas inlet hole and a gas outlet hole formed in a circumferential wall thereof so that the exhaust gas flows in the charging unit through the gas inlet hole and flows out of the ion trapping unit through the gas outlet hole. The gas inlet hole and the gas outlet hole are arranged in such a manner as to at least partially overlap each other when viewed in the given arrangement direction.

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Kasugai, Japan

Keisuke Tashima