Abstract: 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.

Abstract: 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.

Abstract: A ceramic heater is incorporated in a gas sensor capable of detecting the concentration of a specific gas contained in a target gas. The ceramic heater is composed of a heater base member made of ceramic, a heat generating member embedded in the heater base member, and electrode pads electrically connected to contact metal members. The contact metal members are electrically connected to external leads in the gas sensor. In the ceramic heater the electrode pads are formed on a contact area of the outer peripheral surface of the heater base member. The contact area includes a rear end part of the heater base member. On assembling the ceramic heater into the gas sensor, the contact metal members slid on the electrode pads formed in the contact area without directly contacting onto the outer peripheral surface of the heater base member.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A gas sensor equipped with an elastic member which is disposed hermetically in an open end of an air cover joined to a housing. The elastic member has a vertical hole, an air flow path, and lead-retaining holes through which leads pass to establish electric connections between a sensing device and an external device. The air flow path extends from the vertical hole to an outer peripheral surface of the elastic member to direct air having entered at air inlets to the vertical hole. An assembly of an air-permeable filter and a support is fit elastically in the vertical hole of the elastic member, thereby asserting the stability of adhesion between the vertical hole and the filter even if the filter is thermally deteriorated to ensure the waterproofing of the gas sensor.

Abstract: 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.

Abstract: 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.

Abstract: A gas sensor has a sensor element of a cup shape and an insulation electrical heater for heating the sensor element. The insulation electrical heater is placed in an inside of a hollow part of the sensor element. An insulation length extension area is formed on an outer peripheral surface of the insulation electrical heater between electrodes of the insulation electrical heater and a reference electrode metal member tightly bonded onto the sensor element. The insulation length extension area is composed of a plurality of flanges, a rectangle flange part formed in one body, a taper shaped flange part, or a bended flange part.

Abstract: There is provided a gas sensor that includes a sensor element, a heater that comprises an electrode, a housing that holds the sensor element therein, an insulator assembly that surrounds a part of the heater and is constituted of a plurality of insulators, an electric terminal member that is located between the one of the plurality of the insulators and the electrode of the heater, a cover that covers the insulator assembly, a holder for holding the insulator assembly, and an elastic member that is located between the holder and the cover to generate elastic force which is applied at least to the one of the plurality of the insulators to pinch the heater between the one and another one of the plurality of the insulators via the holder so as to bring the electric terminal member into constant electric contact with the electrode of the heater.

Abstract: A gas sensor has a sensor element, a housing, an atmosphere-side cover, lead wirings, an elastic member, and a filter assembly. The elastic member has a vertical-hole and lead-wiring holes. The vertical-hole penetrates the elastic member in an axial direction of the gas sensor. The lead wirings are disposed in the lead-wiring holes. The filter assembly composed of a support member and an air filter is fitted to the vertical-hole of the elastic member. The air filter covers at least an end-side opening part and an outer periphery surface connected to the opening part of the support member. The atmosphere-side cover has fastening parts fastening the elastic member. A part of the air filter covering the outer periphery surface of the support member is fastened between the elastic member and the support member. A part of the air filter is disposed at the inside of the support member.

Abstract: A gas sensor includes a sensing element, a housing, a metal cover, and an oxide layer. The sensing element generates a signal indicative of an oxygen concentration in a measurement gas. The housing holds therein the sensing element with a portion of the sensing element protruding outside of the housing. The metal cover surrounds the portion of the sensing element and is to be exposed the measurement gas. The metal cover has formed therein a gas passage through which the sensing element is also to be exposed to the measurement gas. The oxide layer is formed on at least a surface of the metal cover. With the oxide layer, during operation, at least the metal cover is prevented from being oxidized by the oxygen contained in the measurement gas. Consequently, the oxygen concentration in the measurement gas can be accurately determined based on the signal generated by the sensing element.

Abstract: 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.

Abstract: 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.

Abstract: A gas sensor and a related manufacturing method are disclosed. The gas sensor includes a detecting unit comprised of a concentration detecting element, composed of a solid electrolyte body having inner and outer walls formed with electrodes, a housing, output terminals and a heater, and an output extracting unit comprised of at least signal wires, power conducting wires, output extracting terminals, power conducting terminals, an insulator and a casing. The detecting unit and the output extracting unit are united to each other in the insulator such that the output terminals, holding a base body of the heater in electrical insulation, and the output extracting terminals are conducted to each other and the heater electrodes and the power conducting terminals are conducted to each other upon which a boss portion of the housing is fixedly fitted to a leading end portion of the casing.

Abstract: A gas sensor and a related manufacturing method are disclosed. The gas sensor includes a detecting unit including a concentration detecting element, composed of a solid electrolyte body having inner and outer walls formed with electrodes, a housing, and output terminals, and an output extracting unit including at least signal wires, power conducting wires, output extracting terminals, power conducting terminals, an insulator and a casing. The detecting unit and the output extracting unit are coupled to each other in the insulator such that the output terminals and the output extracting terminals are conducted to each other within the insulator.

Abstract: 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.

Abstract: 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.

Abstract: 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 staying of the water between the inner and outer covers to minimize gap corrosion therebetween.