Ngk Spark Plug Company, Limited

Masaki Iwaya

Takaaki Chosokabe

Kyohei Hayashi

Masahiko Nishi

Hiroshi Matsuzaki

Yoshirou Suematsu

Go Hanzawa

Naoki Yamada

Wakako Takano

Masaru Hayakawa

A sintered body for thermistor element of the invention is a sintered body for thermistor element containing Sr, Y, Mn, Al, Fe, and O, wherein not only respective liquid crystal phases of a perovskite type oxide and a garnet type oxide are contained, but also a liquid crystal phase of at least one of an Sr&#x2014;Al based oxide and an Sr&#x2014;Fe based oxide. FeYOand/or AlYOis selected as the foregoing perovskite type oxide, and at least one member selected from YAlO, AlFeYO, and AlFeYOis selected as the foregoing garnet type oxide, respectively by the powder X-ray diffraction analysis.

Sintered compact for thermistor element, process for producing the same, thermistor element and temperature sensor

A sintered body for thermistor device comprising: at least one element selected from elements of group 3 in a periodic table proviso that La is excluded; at least one element selected from elements of group 2 in a periodic table; Mn; Al; and oxygen, and being substantially free from any transition metal other than Mn and the at least one element selected from elements of group 3 in the periodic table.

Sintered body for thermistor devices, thermistor device and temperature sensor

A temperature sensor () including a cylindrical metal tube () having a front end side blocked, a thermistor element (), and a sheath member () connected to the thermistor element () and held in the inside of the metal tube (), wherein: the metal tube () has a small-diameter portion () located on the front end side and entirely having an inner diameter smaller than the outer diameter of the sheath member (), and a large-diameter portion () located on the rear end side of the small-diameter portion () and having a diameter larger than the outer diameter of the small-diameter portion (); and a thermistor sintered body () is held in the small-diameter portion () and cement () is filled in between a front end of the thermistor sintered body () and a front end of an inner wall of the metal tube () and on the front end side viewed from a rear end surface of the thermistor sintered body ().

Temperature sensor with quick response

A temperature sensor comprising: a housing; a thermo-sensitive element housed in the housing for outputting electric characteristics varying with a temperature, as an electric signal; and a pair of lead wires connected at their one-side ends with the thermo-sensitive element for extracting the electric signal from the thermo-sensitive element to an outside of the housing, wherein at least one of the lead wires is made of a mixed twisted wire including: first electric wires made of a first conductor containing copper; and second electric wires made of a second conductor having a higher bending resistance and a tensile strength than those of the first conductor.

Temperature sensor

A cylindrical metal tube () accommodating therein a thermistor device (), the electric characteristics of which change with temperature, is pushed into, or clamped and fixed to, a sheath portion () positioned on a flange () to the rear of a projection portion () of the flange (), and is laser welded in a circumferential direction. A weld portion (L) formed to bridge the metal tube () and the sheath portion () of the flange () firmly fixes the metal tube () to the flange (). In the temperature sensor () having this construction, the weld portion (L) between the metal tube () and the flange () is not exposed to a high temperature environment. Therefore, oxidation hardly occurs at the weld portion and reliability of air tightness to an exhaust gas can be improved.

A ceramic composition for thermistor exhibiting stable resistance values over a wide temperature range and capable of being used for a prolonged time. The composition is represented by (M.sup.1 M.sup.2 O.sub.3).sub.1-x .multidot.(M.sup.1 AlO.sub.3).sub.x, wherein M.sup.1 is an element selected from the elements of the group 3A excluding La and M.sup.2 is an element of the groups 4A, 5A, 6A, 7A and 8, and wherein the mixing ratio between an electrically conductive substance stable at elevated temperatures and an insulating substance stable at elevated temperatures, may be adjusted. A thermistor formed of the composition is superior in high-temperature stability and can be used over a broad temperature range because its resistance value can be selected to an optimum value.

Ceramic composition for thermistor, thermistor element, and process for

Ceramic composition for thermistor for detecting elevated temperatures which exhibits stable properties at elevated temperatures for permitting use in both oxidizing and reducing atmospheres. In a YCrO.sub.3 based material, Sr or Sm is partly or completely substituted for Y, and Fe and Ti are substituted for part of Cr. Such material enables the production of a thermistor element exhibiting practical, low resistance values at 300.degree. to 1100.degree. C. and also exhibiting stability against changes in the environmental conditions or thermal hysteresis. Generally AMO.sub.3 perovskite structure (A=2A,3A,3B subgroup elements, M=4A,5A,6A,8 subgroup elements) having a combination of n-type and p-type components provides the same property, the subgroup being of IUPAC international periodic table. La-free is preferred and sintering aid may be used.

Ceramic composition for thermistor

A ceramic composition for a thermistor of the formula (M.sup.1.sub.1-x.N.sup.1.sub.x)(P.sup.2.sub.1-y-z.N.sup.2.sub.y.Al.sub.z)O .sub.3 where M.sup.1 is one or more elements selected from the group 3A elements of the Periodic Table excluding La, N.sup.1 is one or more selected from the group 2A elements of the Periodic Table, P.sup.2 is one or more selected from the elements of the groups 4A, 5A, 6A, 7A and 8 of the Periodic Table whose oxides exhibit p-type characteristics, and N.sup.2 is one or more selected from the elements of the groups 4A, 5A, 6A, 7A and 8 whose oxides exhibit n-type characteristics, wherein x, y and z are larger than 0 and smaller than 1 and 0.001.ltoreq.x/(1-y-z)&lt;0.20, 0.05.ltoreq.y/(1-y-z).ltoreq.0.80 and 0&lt;z/(1-y-z).ltoreq.0.90. Thermistor elements are usable within a broad temperature range of 300.degree.-1100.degree. C., have a stable resistance in oxidizing and reducing atmospheres, can prevent deterioration of lead wires, and have superior stability at high temperatures.

Ceramic composition for thermistor and thermistor element

A ceramic composition for thermistor exhibiting stable resistance values over a wide temperature range and capable of being used for a prolonged time. The composition is represented by (M.sup.1 M.sup.2 O.sub.3).sub.1-x .multidot.(M.sup.1 AlO.sub.3).sub.x, wherein M.sup.1 is an element selected from the elements of the group 3A of the International Periodic Table excluding La and M.sup.2 is an element of the groups 4A, 5A, 6A, 7A and 8 of the International Periodic Table, and wherein the mixing ratio between an electrically conductive substance stable at elevated temperatures and an insulating substance stable at elevated temperatures, may be adjusted. A thermistor formed of the composition is superior in high-temperature stability and can be used over a broad temperature range because its resistance value can be selected to an optimum value.

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Gifu, Japan

Masaki Iwaya