Abstract: Disclosed is a sensor, including: a sensor body having a cylindrical case and a sensor element accommodated in the case; a seal member disposed in a rear end part of the case; lead wires electrically connected to the sensor element and extending from inside to outside of the casing through the seal member; and a cylindrical heat shield tube retained to an outer surface of the case and extending rearward from the case so as to circumferentially surround the seal member and parts of the lead wires, characterized in that: the sensor further includes a cylindrical tube cap made of an elastic material and arranged to restrict a rearward movement of the heat shield tube; the tube cap has formed therein at least one lead wire insertion hole through which the lead wires are inserted; and the tube cap is reduced in diameter and held to the lead wires.

Abstract: Disclosed is a sensor, including: a sensor body having a cylindrical case and a sensor element accommodated in the case; a seal member disposed in a rear end part of the case; lead wires electrically connected to the sensor element and extending from inside to outside of the casing through the seal member; and a cylindrical heat shield tube retained to an outer surface of the case and extending rearward from the case so as to circumferentially surround the seal member and parts of the lead wires, characterized in that: the sensor further includes a cylindrical tube cap made of an elastic material and arranged to restrict a rearward movement of the heat shield tube; the tube cap has formed therein at least one lead wire insertion hole through which the lead wires are inserted; and the tube cap is reduced in diameter and held to the lead wires.

Abstract: A gas sensor comprising: the gas sensor element defined; the cylindrical metal shell defined herein; and the protector defined herein, wherein the protector defined herein has a double structure including the cylindrical inner cover portion and the outer cover portion both defined herein, and a leading end portion positioned on a leading end side of the support face of the metal shell, the outer cylindrical portion and the inner cylindrical portion are arranged to construct an inner gas introducing passage for guiding the object gas introduced from the outer gas introducing apertures, between the outer cylindrical portion and the inner cylindrical portion, across a trailing end of the inner cylindrical portion closer to a leading end side, as viewed in an axial direction, than an inner circumferential side end edge of a joining face joining an inner circumference and an outer circumference of a leading end portion of said metal shell, into a clearance between the inner cover portion and the leading end portio

Abstract: A method of producing a gas sensor is provided. The method includes a disposition step of preparing an elastic seal member having a main body portion and a smaller diameter portion that is smaller in outer diameter than the main body portion, disposing the entire main body portion and a part of the smaller diameter portion inside a tubular metallic member and allowing a remaining part of the smaller diameter portion to protrude outward from a rear end of the tubular metallic member, and a crimping step of crimping at least a portion of the tubular metallic member radially inward and thereby compressively deforming the elastic seal member. A gas sensor is also provided.

Abstract: A method of producing a gas sensor is provided. The method includes a disposition step of preparing an elastic seal member having a main body portion and a smaller diameter portion that is smaller in outer diameter than the main body portion, disposing the entire main body portion and a part of the smaller diameter portion inside a tubular metallic member and allowing a remaining part of the smaller diameter portion to protrude outward from a rear end of the tubular metallic member, and a crimping step of crimping at least a portion of the tubular metallic member radially inward and thereby compressively deforming the elastic seal member. A gas sensor is also provided.

Abstract: A gas sensor comprising: a gas sensor element extending in an axial direction; a cylindrical metal shell enclosing said gas sensor element such that a leading end portion of said gas sensor element protrudes from its own leading end; and a protector fixed on said metal shell and covering said leading end portion of said gas sensor element, wherein said protector includes: a cylindrical outer cover portion fixed on said metal shell and having gas introducing apertures; and a cylindrical inner cover portion arranged on an inner side of said outer cover portion and having elastic portions being capable of being elastically deformed by a pushing force acting in an axial direction, and said inner cover portion is so clamped between said metal shell and said outer cover portion that said elastic portions are elastically deformed by said axial pushing force.

Abstract: A gas sensor comprising: the gas sensor element defined; the cylindrical metal shell defined herein; and the protector defined herein, wherein the protector defined herein has a double structure including the cylindrical inner cover portion and the outer cover portion both defined herein, and a leading end portion positioned on a leading end side of the support face of the metal shell, the outer cylindrical portion and the inner cylindrical portion are arranged to construct an inner gas introducing passage for guiding the object gas introduced from the outer gas introducing apertures, between the outer cylindrical portion and the inner cylindrical portion, across a trailing end of the inner cylindrical portion closer to a leading end side, as viewed in an axial direction, than an inner circumferential side end edge of a joining face joining an inner circumference and an outer circumference of a leading end portion of said metal shell, into a clearance between the inner cover portion and the leading end portio

Abstract: A gas sensor comprising: a gas sensor element extending in an axial direction; a cylindrical metal shell enclosing said gas sensor element such that a leading end portion of said gas sensor element protrudes from its own leading end; and, a protector fixed on said metal shell and covering said leading end portion of said gas sensor element, wherein said protector includes: a cylindrical outer cover portion fixed on said metal shell and having gas introducing apertures; and a cylindrical inner cover portion arranged on an inner side of said outer cover portion and having elastic portions being capable of being elastically deformed by a pushing force acting in an axial direction, and said inner cover portion is so clamped between said metal shell and said outer cover portion that said elastic portions are elastically deformed by said axial pushing force.

Abstract: A sensor structure having a metallic terminal member. The metallic terminal member 23 includes press portions 23d and 23e, which press the heating member 3 in a direction intersecting the center axis of a hollow portion 2a of an oxygen detection element 2. Holding means for holding the heating member 3 is formed separately from the metallic terminal member 23. Thus, without use of special heating-member holder means, the metallic terminal member 23 can bring at least a portion of the heating member 3 into contact with the inner wall surface of the hollow portion 2a of the oxygen detection element 2.

Abstract: In a gas sensor, a casing which accommodates a sensing element includes an inner cylindrical member and an outer cylindrical member which are caulked together by means of a caulked portion. The Vickers hardness H1 of the inner cylindrical member is Hv 250 to 430; the Vickers hardness H2 of the outer cylindrical member is Hv 160 to 330; and the hardness difference “H1-H2” is not less than 30. Through employment of the above ranges of H1 and H2, the caulked portion can maintain good airtightness even in a working environment involving, for example, thermal shocks.

Abstract: A gas sensor including a detecting element having electrodes on first and second surfaces of an oxygen ion conductive solid-state electrolyte; a main fitting having a fitting portion to be fitted into a mounting hole formed on a wall of the pipe defining a flow path for a gas-to-be-measured for holding the detecting element in such manner that the first surface is disposed via the mounting hole at an inner position of the pipe with respect to the fitting portion; a cylindrical cover of which one end is connected to an outer position of the pipe with respect to the fitting portion of the main fitting and the other end is provided with a cylindrical sealing member having an air hole for introducing air to the second surface on one end and a through hole through which a lead connected to both electrodes of the detecting element passes on the other end; and a water repellant filter having gas permeability for closing the air hole, characterized in that the water repellant filter is formed in a sheet shape and mou

Abstract: An oxygen sensor is constituted by a ceramic separator being placed so that the rear thereof enters the inside of a filter holding part and the front enters the inside of a casing and formed with a plurality of lead insertion holes axially penetrating the ceramic separator and an elastic seal member being fitted elastically into a rear opening of the filter holding part and having seal lead insertion holes for inserting leads for sealing the gap between the outer faces of the leads and the inner face of the filter holding part. The rear end face of the ceramic separator is positioned on the rear side behind a gas introduction hole in the axial direction and a predetermined gap is formed between the elastic seal member and the ceramic separator at least at the lead insertion position.

Abstract: A sensor structure which reduces the resistance of insertion in the course of insertion of a metallic terminal member into the hollow portion of an oxygen detection element so as to enable smooth assembly and such that portions of the metallic terminal member become less susceptible to plastic deformation. An attachment portion 23c of a metallic terminal member 23 is in contact with the inner wall surface of a hollow portion 2a of an oxygen detection element 2, directly or indirectly via another member, at opposite sides thereof located along the direction of contact. Also, a gap is formed between an attachment portion 23c and the inner wall surface at opposite sides of the attachment portion 23c located along the direction of gap formation.

Abstract: An oxygen sensor is constituted by a ceramic separator being placed so that the rear thereof enters the inside of a filter holding part and the front enters the inside of a casing and formed with a plurality of lead insertion holes axially penetrating the ceramic separator and an elastic seal member being fitted elastically into a rear opening of the filter holding part and having seal lead insertion holes for inserting leads for sealing the gap between the outer faces of the leads and the inner face of the filter holding part. The rear end face of the ceramic separator is positioned on the rear side behind a gas introduction hole in the axial direction and a predetermined gap is formed between the elastic seal member and the ceramic separator at least at the lead insertion position.

Abstract: The invention reduces the activation time of an oxygen sensor with a heater through rapid heating of an oxygen sensing element. A shaft-like heating member is inserted and fixed into an oxygen sensing element of a hollow shaft-like member while a terminal member intervenes therebetween. A heating portion is locally formed at an extreme end of the heating member. A surface of the heating portion is elastically pressed against an element inner wall, thereby establishing a laterally-abutting structure. A positioning projection is formed on an internal electrode connecting portion and projects toward the interior of the internal electrode connecting portion. The positioning projection is adapted to position the heating element within a hollow portion of the oxygen sensing element such that the axis thereof becomes substantially parallel to the axis of the hollow portion.

Abstract: A gas sensor including a detecting element having electrodes on first and second surfaces of an oxygen ion conductive solid-state electrolyte; a main fitting having a fitting portion to be fitted into a mounting hole formed on a wall of the pipe defining a flow path for a gas-to-be-measured for holding the detecting element in such manner that the first surface is disposed via the mounting hole at an inner position of the pipe with respect to the fitting portion; a cylindrical cover of which one end is connected to an outer position of the pipe with respect to the fitting portion of the main fitting and the other end is provided with a cylindrical sealing member having an air hole for introducing air to the second surface on one end and a through hole through which a lead connected to both electrodes of the detecting element passes on the other end; and a water repellant filter having gas permeability for closing the air hole, characterized in that the water repellant filter is formed in a sheet shape and mou

Abstract: A shaft-like heating member is inserted into and fixed to an oxygen sensing element of a hollowed shaft-like member, together with of a terminal member. A heating portion is located at a portion of the heating member closer to the extreme end thereof. The surface of the heating portion is resiliently pressed on the element inner wall in a side-abutting fashion. In this case, a guide mainly gives rise to the elastic force. With such a side-abutting structure, heat generated in the heating portion is directly transferred to the oxygen sensing element, and heats it. Heat radiated from a portion in the vicinity of its contact position additively heats the oxygen sensing element. Temperature of the oxygen sensor quickly reaches an activation temperature.