Ngk Spark Plug Company, Limited

Yoshiaki Kuroki

Takao Kojima

Shinya Awano

Kunio Yanagi

Akio Takami

Toshitaka Matsuura

Hiroyuki Hayashi

Yoshiro Noda

Yutaka Adachi

Ryohei Aoki

Koichi Imaeda

Tomohiro Mabuchi

Sinya Awano

Masashi Ando

Hiroshi Matsuzaki

Toshifumi Sekiya

Keisuke Makino

Akira Nakano

A gas sensor element having an element body, the element body including: a ceramic heater having ceramic layers and a heater element embedded in the ceramic layers; and a solid electrolyte layer including a detection section covered by a pair of electrodes, the solid electrolyte layer being laminated together with the ceramic heater. Furthermore, the element body has a width at a front portion including the detection section smaller than at a rear portion, and at least both side edge faces of the front portion of the element body are covered with a porous layer.

Lamination-type gas sensor element and gas sensor

A solid electrolyte layer or body capable of being co-fired with an insulating ceramic substrate or body to be used as a gas sensor laminate. The gas sensor laminate is preferably composed of an alumina substrate () and an oxygen-ion conductive solid electrolyte layer () bonded to the alumina substrate () by firing. The oxygen-ion conductive solid electrolyte layer or body is formed from partially or wholly stabilized zirconia, which layer contains alumina in an amount of 10% to 80% by weight, particularly 30% to 75% by weight. In this manner, another ceramic layer; particularly, a ceramic layer () of alumina can further be bonded to the oxygen-ion conductive solid electrolyte layer. The relative density of the ceramic layer can be 60% to 99.5%, preferably 80% to 99.5%.

Solid electrolyte containing insulating grains for gas sensor

A sensor element including an insulative base (), a heating resistor (), an oxygen pump cell (), an oxygen detection cell (), and a diffusion-chamber-forming member () having a rate-controlling introduction portion () and defining a diffusion chamber () in cooperation with electrodes (), wherein these components have been subjected to simultaneous firing (i.e., cofiring) to form a unitary sensor element. A partition wall (), which extends from the diffusion-chamber-forming member and is made of alumina, is joined to a surface of a solid electrolyte () between two electrodes () of an Ip cell. Preferably, a region within 20 &#x3bc;m from the plane of junction joining the partition wall () to the solid electrolyte () contains no portion whose amount of non-alumina substances exceeds by 2% by mass (by weight) or more the amount of non-alumina substances of the diffusion-chamber-forming member ().

Gas sensor element having at least two cells

A multi-layer gas sensor element is described which comprises a solid electrolytic member, a substrate, and a porous member, wherein each of the substrate and the porous member has a thickness larger than that of the solid electrolytic member with respect to a lamination direction; the substrate and the porous member face each other and sandwich the solid electrolytic member; a ceramic component constituting the substrate in the highest volume percent is the same as the ceramic component constituting the porous member in the highest volume percent thereof; and the volume percent (R2) of the ceramic component contained in the porous member is 80% or more the volume percent (R1) of the ceramic component contained in the substrate.

Multi-layer gas sensor element and gas sensor comprising the same

A solid electrolyte layer or body capable of being co-fired with an insulating ceramic substrate or body to be used as a gas sensor laminate. The gas sensor laminate is preferably composed of an alumina substrate ( ) and an oxygen-ion conductive solid electrolyte layer ( ) bonded to the alumina substrate ( ) by firing. The oxygen-ion conductive solid electrolyte layer or body is formed from partially or wholly stabilized zirconia, which layer contains alumina in an amount of 10% to 80% by weight, particularly 30% to 75% by weight. In this manner, another ceramic layer; particularly, a ceramic layer ( ) of alumina can further be bonded to the oxygen-ion conductive solid electrolyte layer. The relative density of the ceramic layer can be 60% to 99.5%, preferably 80% to 99.5%.

Solid electrolyte containing insulating ceramic grains for gas sensor

A ceramic heater for heating a sensor such as an oxygen sensor has a ceramic substrate and a heater pattern formed on the substrate. A heater pattern 22 is tightly interposed between first and second alumina substrates 15 and 21. This heater pattern 22 has a meandering heating section 25 and a pair of leads 26 for connecting both ends of the heating section 25 to two terminals at the base side end. The heating section 25 is divided into a tip side subsection 25a located near the tip side end of the device, and a base side subsection 25b. Specifically, the wire width is made greater in the tip side subsection 25a than in the base side subsection 25b so that the resistance per unit length is lower in the tip side subsection 25a. The thus-designed heater section 25 produces a less amount of heat in the tip side subsection than in the base side subsection, and this distribution of heat generation can reduce the possibility of cracks and breakage of a wire.

Ceramic heater and oxygen sensor

In an oxygen sensor of the type having an oxygen ion conductive tube of solid electrolyte, a ceramic heater disposed within the oxygen ion conductive tube for heating the same is in the form of a quadrangular prism or a bar of a rectangular cross section. The ceramic heater is formed by piling up ceramic green sheets with metallic thick-film patterns for heat generating resistors interposed between adjacent two of the ceramic green sheets. The ceramic heater is so shaped as to satisfy the relation of b/a=0.75.about.1 where 'a' is the width and 'b' is the thickness of the ceramic heater. The metallic thick films, which the metallic thick-film patterns are turned to by firing, are arranged so as to be parallel to the side surfaces opposed in the thickness direction of the ceramic heater.

Ceramic heater for oxygen sensor of the type having oxygen ion

A gas sensor has a ceramic substrate carrying a first ceramic layer formed thereon and a second ceramic layer formed on the first layer, the two layers having successive setbacks from one edge of the substrate so as to form a staircase-like edge structure, and a gas-sensitive layer is formed on the staircase-like edge portion of said substrate, height of said gas-sensitive layer above the substrate being less than the thickness of the first ceramic layer.

Gas sensor

A gas sensor has a heater circuit with a voltage-dividing element, and a voltage to energize the heater circuit is applied through a resistive lead wire element, while a sensor voltage to measure the resistance of a gas-sensitive element is branched from the heater circuit.

Growing community of inventors

Aichi, Japan

Yoshiaki Kuroki