Abstract: A gas sensor including: a cylindrical metal shell; a detection element having a detection portion provided on a front end side thereof; the detection element being fixed inside the metal shell while the detection portion of the detection element protrudes from a front end side of the metal shell; and an element protection cap having ventholes, the element protection cap being fixed to the metal shell so that the detection portion of the detection element is covered with the element protection cap. A crimping cylindrical portion is provided which extends to a front end side of the metal shell. A protrusion portion of the element protection cap which abuts a metal ring packing is provided with concave and convex portions outward along an outer circumferential direction. As such, the metal ring packing is deformed so as to be interlocked with the concave and convex portions when the crimping cylindrical portion is compressively deformed.

Abstract: A gas sensor 1 includes an outer cylinder 18, a metallic shell 3, and a sensor element 2. The metallic shell 3 is disposed inside the outer cylinder 18. The sensor element 2 is disposed in a through-hole 30 formed in the metallic shell 3 and is adapted to detect a component of a gas to be measured. A sealing material layer 32 is mainly made of glass and is disposed between the inner surface of the metallic shell 3 and the outer surface of the sensor element 2. A cushion layer 34 formed of a porous inorganic substance is disposed in contact with the end of the sealing material layer 32 on the front-end side with respect to the axial direction of the sensor element 2. A cushion layer 33 formed of talc glass is disposed in contact with the end of the sealing material layer 32 on the rear-end side with respect to the axial direction of the sensor element 2.

Abstract: A gas sensor 1 includes an outer cylinder 18, a metallic shell 3, and a sensor element 2. The metallic shell 3 is disposed inside the outer cylinder 18. The sensor element 2 is disposed in a through-hole 30 formed in the metallic shell 3 and is adapted to detect a component of a gas to be measured. A sealing material layer 32 is mainly made of glass and is disposed between the outer surface of the sensor element 2 and the inner surface of the metallic shell 3 or between the outer surface of the sensor element 2 and the inner surface of an insulator 4 disposed between the metallic shell 3 and the sensor element 2. Cushion layer 33 and 34 are each made of a porous inorganic substance. At least either the cushion layer 33 or 34 is disposed so as to abut one end of the sealing material layer 32.

Abstract: A gas sensor has a structure in which an insulator is disposed inside a metallic shell, and a sensor element is disposed inside the insulator. A cavity is formed in the insulator to surround the sensor element. A sealing material mainly formed of glass is charged into the cavity in order to establish sealing between the inner surface of the insulator and the outer surface of the sensor element. The sensor element has a rectangular cross section, and the inner surface of the insulator defining the cavity has a sectional profile corresponding to the sectional profile of the sensor element.

Abstract: A connection device for a ceramic gas sensor element includes a sensor assembly and a ring member. The sensor assembly has a ceramic element with a thickness t, an electrical connection portion formed on a side of the ceramic element, and at least one electrical lead in contact with the electrical connection portion, wherein the sensor assembly defines an outer dimension at a position corresponding to the electrical connection portion. The ring member is disposed around the sensor assembly to hold the at least one electrical lead in contact with the electrical connection portion such that the ring member has an inner dimension at a position corresponding to the connection portion that is smaller than the outer dimension of the sensor element. The ring member defines an axial length L that contacts the sensor assembly such that the thickness t and the axial length L satisfy the relation 0.23≦L/t≦13.

Abstract: A heat-resisting metal-sheathed cable for a sensor includes: an outer sheathing tube made of a heat-resisting metal; an inner sheathing tube made of a heat-resisting metal and disposed within the outer sheathing tube with a predetermined gap that includes an open ventilation passage between an inner circumferential surface of the outer sheathing tube and an outer circumferential surface of the inner sheathing tube; at least one conductor disposed within the inner sheathing tube; and a mass of insulating powder disposed within the inner sheathing tube and around the at least one conductor.

Abstract: A terminal fixing structure which includes a cylindrical ceramic base with a conductive contact on the side and a metal thermal with a pair of resilient arms for holding the side of the ceramic base and for contacting the conductive contact. The ceramic base has an engaging receptor on the side and each of the arms has an engaging portion for engaging with the receptor. Since the engaging receptor (e.g., ring grooves) of the ceramic base is firmly engaged with the engaging portion (e.g., teeth), the ceramic base and the terminal will not be separated from each other by a vibration, etc. An oxygen sensor using this terminal fixing structure is one possible application.

Abstract: An electrolytic oxygen sensor in which the atmosphere is admitted to one side of the solid electrolyte through an air-permeable spacer through a dual concentric tube structure. Holes are formed in the inner tube to complete the air flow to the atmosphere. The small size of the holes prevent the entry of water and oil contaminants.

Abstract: An oxygen sensor including an oxygen sensing element having one closed end and inner and outer electrode layers formed on the inner and outer surfaces thereof, an output withdrawing lead wire electrically connected to the inner electrode layer formed on the inner surface of the oxygen sensing element, and a metallic terminal disposed in connection between the output withdrawing lead wire and the inner electrode layer. The metallic terminal includes opposed resilient portions separated by a gap and disposed in contact with the inner periphery of the inner electrode layer to apply a radial force to the inner electrode layer, whereby not only the damage of the oxygen sensing element is prevented but also the mounting operation can be done easily without threaded insertion of the metallic terminal.

Abstract: A precombustion chamber provided with an arrangement for thermally insulating a cylinder head of an internal combustion engine from a combustion gas in the precombustion chamber comprising: (a) a hollow ceramic body which provides a precombustion chamber and is disposed within the hollow space for the precombustion chamber; (b) a hollow fitting member disposed surrounding the hollow ceramic body within the hollow space for mitigating and absorbing the stress produced between the cylinder head and the hollow ceramic body; and (c) seal means for sealing a space between the hollow ceramic body and the fitting member to provide a closed space therebetween, wherein said hollow fitting member is tightly secured to the hollow ceramic body through the seal means.

Abstract: A gas sensor including a gas sensor body in which is centrally inserted a gas detecting element and which permits the gas sensor itself to be attached to other members; a protective sleeve attached to an end portion of the gas sensor body; a seal member formed of a heat-resistant synthetic resin, the seal member being disposed inside an end portion on a lead wire draw-out side of the protective sleeve, with a lead wire extending through the seal member; and a spring member mounted within the protective sleeve for urging the seal member liquid-tightly against the lead wire draw-out side end portion of the protective sleeve. Since the seal member disposed in an end portion of the protective sleeve is formed of a heat-resistant synthetic resin, the durability thereof is improved even where high temperature gases such as the exhaust gases of internal combustion engines or the like are to be detected.

Abstract: The oxygen sensor for exhaust gas of internal combustion engine includes a solid electrolyte tube having an inner electrode coated on the inner surface of said electrolyte tube outer electrode formed on outer surface of said electrolyte tube and disposed on the outside surface thereof so as to come in contact with exhaust gas and a metallic protective tube coaxially surrounding said electrode with a spacing therefrom. The sidewall of the protective tube has two similarly arranged matrices of holes, each hole being made by cutting an arcuate edge on the sidewall and bending the thus cut portion toward the inside of the protective tube, and the holes of one matrix are interposed among the holes of the other matrix while being offset therefrom in both the longitudinal and circumferential directions of the protective tube.

Abstract: An oxygen detector for detecting concentration of oxygen in exhaust gas delivered from various kinds of combustion apparatus inclusive of an internal combustion engine or the like and comprising a resilient portion operative to apply a tensile or compressive force to a coil-shaped terminal of a center conductor threadedly engaged with the threaded open end of an inner electrode layer of an oxygen detection element.