Ngk Spark Plug Company, Limited

Tomohiro Tajima

Kunihiko Yonezu

Hisaharu Nishio

Takaya Yoshikawa

Masao Tsuzuki

Norimasa Osawa

Noboru Ishida

Kentaro Mori

Satoshi Ishikawa

Toshiya Matsuoka

Tomoki Fujii

Masanori Otsubo

A gas sensor () includes at least a sensor element () which measures the concentration of a specific gas component, a housing () which accommodates the sensor element (), and a base portion () which is attached to the housing and is formed of resin. The base portion includes a first base portion () which is a portion of the base portion located on the side toward the housing and which is molded integrally with the housing, and a second base portion () which is molded separately from the first base portion, which is a portion of the base portion located opposite the housing, and which has a connector portion () in which a plurality of terminals () electrically connected to the sensor element are disposed such that they extend in a direction intersecting the insertion direction of the sensor element.

Gas sensor

A thin plate member which has a groove portion recessed toward the inside in a radial direction with a gap interposed between the thin plate member and the outer surface of a site on the front end side of a main body section. At least one end of the thin plate member is joined to the outer surface of the main body section and is provided radially outside the site on the front end side of the main body section. A seal member is disposed in the groove portion and has elasticity due to resin. Since the gap functions as a heat-insulating layer and is interposed between the seal member and the main body section, heat conduction from the main body section, that is, heat conduction through a first pathway is reduced, and thus deterioration of the seal member due to heat is suppressed.

A gas sensor () has an inner protector () and an outer protector (); the inner protector () has an inner wall portion () having an inner gas inlet () for introducing gas to be measured into the interior of the inner protector (); the outer protector () has an outer wall portion () having an outer gas inlet () for introducing the gas to be measured into the interior of the outer protector (); a clearance of 1.35 mm or less is provided between the detection portion () and at least a portion of the inner wall portion (); and when the gas sensor () is in use, the inner protector () is higher in temperature than the outer protector ().

A sensor control apparatus including a gas sensor having a sensor element, a housing and a base part formed of a resin. The apparatus includes a heating part and a control part. When the control part determines that a predetermined automatic stop condition has been satisfied, the control part switches from a control for maintaining the temperature of the sensor element at an activating temperature to a control in a stop state for reducing at least one of voltage and current supplied to the heating part so as to set a temperature of the base part to a value equal to or lower than a shape holding temperature of the resin. Also disclosed is a sensor control method for holding a temperature of a sensor element to an activating temperature.

Sensor control apparatus and sensor control method

A gas sensor () includes a gas sensor element () extending in an axial direction (O), having a detection portion () provided at a front end thereof, and having electrode pads () provided at a rear end thereof; connection terminals () electrically connected to the respective electrode pads; and a cover () covering the rear end of the gas sensor element and the connection terminals. The cover integrally has a connector portion () having an opening () which allows an external connector to be inserted thereinto and removed therefrom in a predetermined direction, and has a connector terminal member () which can be inserted into the opening. The connector terminal member has a plurality of connector terminals () to be electrically connected to the respective connection terminals, and an insulator () integrally molded with the connector terminals. Also disclosed is a method for manufacturing the gas sensor.

Gas sensor and manufacturing method therefor

A gas sensor () includes a gas sensor element () extending in the direction of an axis O, and a housing () made of metal, radially surrounding the gas sensor element, and adapted for inserting at least partially into a sensor-mounting hole () of a mounting body (). The gas sensor () further includes a resin member () which radially surrounds the housing at least partially and having a contact portion (C) in contact with the housing that is at least partially disposed axially frontward with respect to the outer surface of the mounting body () around the sensor-mounting hole, and a heat sink member () that is in contact with the housing at an axial position the same as or located frontward of the axial position of the front end of the contact portion.

A gas sensor including a gas sensor element that extends in an axial direction and has a detection section at a front-end side thereof, and an electrode pad at a rear-end side thereof; a connection terminal that is electrically connected to the electrode pad; and an insulated separator that extends along the axial direction and has an inserting hole into which the connection terminal is inserted. An element side section is arranged within the inserting hole and is connected the electrode pad, and an external circuit side section extends further to the outside in a diametrical direction than an outer surface of the separator through one or more first bending sections from the element side section.

A sensor control apparatus () includes a full-range gas sensor composed of an oxygen concentration detection cell having a pair of electrodes () and an oxygen pump cell having a pair of electrodes (). In an electric circuit section (), an Ip current flowing between the electrodes () is controlled such that an electromotive force Vs produced between the electrodes () becomes equal to a reference voltage. The reference voltage is usually set to a first reference voltage. However, when the subject gas is air, the reference voltage is set to a second reference voltage. Humidity of the subject gas is detected on the basis of an error &#x394;Ip between an Ip current detected when the reference voltage is set to the first reference voltage, and an Ip current detected when the reference voltage is set to the second reference voltage.

Gas-concentration/humidity detection apparatus

An intake system for an internal combustion engine includes an intake passage connected with an intake port of the internal combustion engine; an EGR passage merged with the intake passage at a junction portion; a gas sensor attached to the intake passage and configured to detect a concentration of specific gas; and a control section configured to control the internal combustion engine on the basis of an output signal of the gas sensor. A diameter-enlarged portion having an inner diameter larger than an inner diameter of the junction portion is formed at a portion of the intake passage which is located on a downstream side of the junction portion. The gas sensor is located downstream from the diameter-enlarged portion.

Growing community of inventors

Kasugai, Japan

Tomohiro Tajima