Denso Corporation

Nippondenso Co., Ltd.

Masanobu Yamauchi

Kenji Fukaya

Isao Watanabe

Kiyomi Kobayashi

Motoaki Satou

Namitsugu Fujii

Takashi Kojima

Hirokazu Yamada

Toshihiro Sakawa

The gas sensor includes a sensor element, a heater for heating the sensor element, the heater having a roughly cylindrical shape, a housing into which the sensor element is inserted to be held therein, and a terminal unit disposed so as to cover a rear end portion of the heater on a rear end side of the housing. The terminal unit includes a pair of insulators, a pair of metal terminals each of which is located inside a corresponding one of the pair of the insulators and in contact with a corresponding one of a pair of electrode pads provided on a surface of the rear end portion of the heater, and a pressing member pressing the pair of the insulators in a direction that the pair of the insulators approach each other. The pair of the insulators are located out of contact with each other. The rear end portion of the heater is contact-supported at at least three contact points by the terminal unit.

Gas sensor

A gas sensor comprises a sensing element detecting a gas concentration, a heater heating up the sensing element, an element-holding body holding the sensing element, and an atmosphere-side insulator. A pair of contact fittings is arranged between a base end part of the sensing element or the heater and an inner wall surface of the atmosphere-side insulator, and contacts a pair of electrodes disposed on the sensing element or the heater so as to press thereof. The contact fitting is provided with a base plate contacting the inner wall surface and an electrode contact member located to each of the electrodes and contacting the electrode. The gas sensor comprises suppressing means for suppressing the contact fittings from shifting relative to the electrodes in directions crossing the longitudinal direction. As an example, suppressing means are a plurality of fixing spring members pressing the inner wall surface from inside the insulator.

Gas sensor for use in detecting concentration of gas

A gas sensor designed to ensure waterproofing and air ventilation is provided which includes a rubber bush fitted in an end of an air cover joined to a housing. The rubber bush has formed in a base portion thereof lead-pass holes and in a top portion thereof an air flow path through which air is introduced into an air chamber in the gas sensor. The air cover is crimped circumferentially to provide an elastic nip only to the base portion of the rubber bush, thereby ensuring tight fits of the leads in the lead-pass holes without deforming the air flow path undesirably. An ventilation filter is fit on a neck of the rubber bush between the base portion and the top portion in communication with the air flow path, thus ensuring the stability of entrance of the air into the air flow path through the ventilation filter.

Structure of gas sensor designed to ensure stability of waterproofing and air ventilation

An anti-corrosion structure of a gas sensor is provided. The gas sensor includes a hollow cylindrical air cover assembly made up of an inner and an outer cover. The air cover assembly has formed therein air inlets through which air is admitted into the gas sensor. The inner and outer covers are joined together through at least one crimped portion which defines a water drain path extending from the air inlets to outside the air cover assembly, thereby draining the water entering at the air inlets out of the gas sensor. This avoids accumulation of the water between the inner and outer covers to minimize gap corrosion therebetween.

Anti-corrosion structure of gas sensor

A gas sensor having an elastic insulating member including a longitudinal hole for receiving an air permeability filter assembly and a passage portion communications between the longitudinal hole and an outer side thereof.

A gas sensor is disclosed having an element holder body with which a sensor element is fixedly supported, and an atmosphere-side insulator covering a base portion of the sensor element and providing electrical connection between lead wires and terminal electrodes of the sensor element. The element holder body includes a housing and an element-side insulator fixedly mounted in the housing. The atmosphere-side insulator incorporates therein a plurality of spring terminals held in electrical contact with the electrode terminals of the sensor element. At least one of the element holder body and the atmosphere-side insulator carries thereon convexed portions with which the atmosphere-side insulator can tilt with respect to the element holder body.

A gas sensor includes a sensor element, a housing, a hollow porcelain insulator, electrical contacts, a holder, and an air cover. The sensor element is retained inside the housing through the porcelain insulator. The electrical contacts are retained firmly within the porcelain insulator in electrical connection with the sensor element. The air cover is joined to the housing to cover the porcelain insulator. The holder is fit on the porcelain insulator and has stopper springs which are in elastic abutment with an inner shoulder surface of the air cover, thereby stopping the porcelain insulator from moving vertically when the contacts are pulled undesirably through lead wires in order to ensure the stability of electrical connection with the sensor element.

Structure of gas sensor ensuring stability of electrical connection

A powder filler is stuffed in a filler space defined between a housing and a gas sensing element so as to airtightly seal a clearance between the housing and the gas sensing element. The powder filler contains grains whose diameter is in a range from 80 &#x3bc;m to 5,000 &#x3bc;m when measured before being stuffed into the filler space. A weight percentage of the grains having the diameter of 80 &#x3bc;m to 5,000 &#x3bc;m is equal to or larger than 80% with respect to an overall weight of the powder filler.

A gas sensor has a sensor element inserted in a cylindrical housing. A measured gas cover, provided at a distal end side of the housing, forms a measured gas environment at a distal end side of the sensor element. An atmospheric air cover, provided at a proximal end side of the housing, forms an atmospheric air environment at a proximal end side of the sensor element. A clearance between an inside surface of the housing and an outside surface of the sensor element is gastightly sealed with a sealing member including a plurality of powder filler layers to separate or isolate the measured gas environment from the atmospheric air environment.

A gas sensing element comprises a solid electrolytic element, a measured gas sensing electrode provided on an outer surface of the solid electrolytic element, and a reference gas sensing electrode facing a reference gas chamber. A heater is accommodated in the reference gas chamber. A contact portion is provided on an outer cylindrical surface of the heater so that the contact portion is brought into contact with an inside surface of the solid electrolytic element defining the reference gas chamber. A heating peak position of the heater is in the vicinity of the contact portion.

A gas sensor includes a sensor element. The sensor element has a solid electrolytic member, a measurement electrode, and a reference electrode. The measurement electrode is provided on the solid electrolytic member, and is exposed to a measurement gas. The reference electrode is provided on the solid electrolytic member, and is exposed to a reference gas. A heater operates for heating the sensor element. A portion of the heater contacts a portion of the sensor element. The temperature of the sensor element is increased to 300&deg; C. by the heater in ten seconds after the start of activation of the heater.

A gas sensor measuring a given component content in a gas is provided which has an outer and an inner metallic cover, a sensing unit, and an insulator. The sensing unit consists of a measuring electrode to be exposed to the gas to be measured and a reference electrode to be exposed to a reference gas in a reference gas chamber. The measuring electrode and the reference electrode are disposed adjacent each other through a solid electrolyte body. The inner metallic cover is installed on an end of a sensor housing. The outer metallic cover is installed on the periphery of the inner metallic cover. The insulator is mounted within the inner metallic cover and has formed therein holes through which sensor signal pickup leads pass. The insulator has an outer wall different in geometry from an inner wall of the inner metallic cover to define a portion of a reference gas passage therebetween which leads to the reference gas chamber.

Structure of gas sensor

An air fuel ratio sensor having an externally located heat source and an optical fiber heat introduction member. The heat introduction member is inserted into an inside chamber of a sensor element having a U-shaped cross section, and is connected to the external heat source outside the sensor element for introducing heat from the external heat source into the inside chamber. The heat introduction member is further connected to a temperature detector outside the sensor body. Accordingly, an air fuel ratio sensor can have sufficient durability and sufficient starting performance, and a temperature inside the sensor element can be readily detected.

Air fuel ratio sensor with externally located heat source

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.

Oxygen concentration sensor

In an oxygen gas sensor having a variable electrical characteristic dependent upon ambient oxygen concentration, a ceramic holding member having a hole for holding a plate sensor sensor element is disposed in a housing with the element inserted into the housing. During sensor assembly, powder is filled under pressure in the housing between a pressurized member and the ceramic holding member. The ceramic holding member has an inclined surface descending directly from an upper opening end of the holding hole to form an obtuse angle between the sensor element and the inclined surface, so that the powder can flow on the inclined surface smoothly during the powder filling and powder compressing operations. By taking this construction it is possible to provide an oxygen concentration sensor with no cracking of the element and easy mounting of the sensor element to the housing.

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Kariya, Japan

Masanobu Yamauchi