Ngk Spark Plug Company, Limited

Keiichi Noda

Yuichi Yamada

Hisaharu Nishio

Katsuhisa Yabuta

Shingo Ito

Daisuke Tahira

Kazuo Taguchi

Atsunori Okada

Koichi Shimamura

Koji Kano

Yasuhiro Ishiguro

Makoto Kume

Shoji Akatsuka

Mitsuo Kusa

Keiichi Nodo

Ryuta Fukano

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.

Sensor having tube cap restricting rearward movement of heat shield tube

A method for manufacturing a gas sensor includes: disposing a tubular holder and a tubular compact in a tubular metallic shell defining a through hole, the tubular holder defining a first insertion hole, and the tubular compact defining a second insertion hole; preparing a preliminary assembly in which a pin is inserted into the first insertion hole and the second insertion hole; pulling out the pin from the first insertion hole and the second insertion hole and inserting a sensor element into the first insertion hole and the second insertion hole such that a forward end of the pin will come into contact with an end of the sensor element; compressing the compact to thereby fix the sensor element inside of the metallic shell; welding a protection sleeve to the metallic shell to thereby form a semi-assembly; and combining the semi-assembly with another semi-assembly to thereby form the gas sensor.

Method for manufacturing sensor intermediate product and method for manufacturing sensor

A method for manufacturing a sensor intermediate product includes: disposing a tubular holder and a tubular compact in a tubular metallic shell, and inserting a metallic pin into a first insertion hole of the holder and a second insertion hole of the compact; compressing the compact so as to form a filling member intermediate having a shape which brings the filling member intermediate into pressure contact with the inner wall surface of the metallic shell and allows removal of the metallic pin from the second insertion hole; pulling out the metallic pin from the first insertion hole and the second insertion hole; inserting a sensor element into the first insertion hole and the second insertion hole; and compressing the filling member intermediate to thereby form a filling member which fixes the sensor element inside of the metallic shell.

Disclosed is a gas sensor including a metal shell, a ceramic holder placed in an axial inner hole of the metal shell and a sensor element inserted through an insertion hole of the ceramic holder. The ceramic holder has a recessed hole recessed toward the rear from a front-facing surface of the ceramic holder. The sensor element has, at a front end part thereof, a detection portion covered with a porous protection layer such that a rear end part of the protection layer is accommodated in the recessed hole with a space left therebetween. Further, the ceramic holder has a front circumferential edge defined between an inner circumferential surface of the recessed hole and the front-facing surface of the ceramic holder such that the whole of the front circumferential edge is located radially inside of a radially innermost position of the axial hole.

Gas sensor

A gas sensor includes an outer cylinder a metallic shell and a sensor element The metallic shell is disposed inside the outer cylinder The sensor element is disposed in a through-hole formed in the metallic shell and is adapted to detect a component of a gas to be measured. A sealing material layer is mainly made of glass and is disposed between the inner surface of the metallic shell and the outer surface of the sensor element A cushion layer formed of a porous inorganic substance is disposed in contact with the end of the sealing material layer on the front-end side with respect to the axial direction of the sensor element A cushion layer formed of talc glass is disposed in contact with the end of the sealing material layer on the rear-end side with respect to the axial direction of the sensor element A gas sensor according to the present invention is especially adapted for use in a motorcycle and includes a sensor element having lower susceptibility to mechanical shock or thermal stress induced by different rates of contraction between a sealing material layer and an adjacent component element as well as excellent durability.

Gas sensor with multiple mechanical and thermal shock cushion layers

A gas sensor includes an outer cylinder a metallic shell and a sensor element The metallic shell is disposed inside the outer cylinder The sensor element is disposed in a through-hole formed in the metallic shell and is adapted to detect a component of a gas to be measured. A sealing material layer is mainly made of glass and is disposed between the outer surface of the sensor element and the inner surface of the metallic shell or between the outer surface of the sensor element and the inner surface of an insulator disposed between the metallic shell and the sensor element Cushion layer and are each made of a porous inorganic substance. At least either the cushion layer or is disposed so as to abut one end of the sealing material layer A gas sensor according to the present invention includes a sensor element featuring lower susceptibility to mechanical shock or thermal stress induced by different rates of contraction between a sealing material layer and an adjacent component element, as well as excellent durability.

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.

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Ichinomiya, Japan

Keiichi Noda