Ngk Spark Plug Company, Limited

Masataka Taguchi

Yasuhiro Fujita

Takahiro Hayashi

Yoshiaki Matsubara

Hitoshi Iimi

Noboru Ishida

Takaya Yoshikawa

Masashi Ando

Hiromichi Hayashi

Junji Kawai

Daisuke Miyata

Tetsuma Shimozato

Hidekazu Katou

Kenji Hayashi

Shinji Tanabe

The present invention aims to provide a gas sensor that can favorably be assembled by proper positioning of a connection terminal relative to a separator and a subassembly unit for such a gas sensor. In an oxygen sensor, a separator has protruding portions formed on a surface of a front end part thereof; an outer connection terminal has an outer fitting portion fixed to outer circumferential surfaces of the protruding portions under its biasing force; and an inner connection terminal has an inner fitting portion fixed to inner circumferential surfaces of the protruding portions under its biasing force. Thus, it is less likely that the outer and inner connection terminals will be displaced in position relative to the separator and is possible to allow proper positioning of the outer and inner connection terminals.

Gas sensor and subassembly unit therefor

A gas sensor comprises a cylindrical metallic housing, a sensor element having at a front end thereof a sensing portion and disposed axially in the housing with the sensing portion protruded from a front end of the housing, a sensor terminal fitted to a rear end of the sensor element to produce a signal output from the sensing portion, a first protective cover attached to a front end portion of the housing to cover the sensing portion and a second protective cover attached to a rear end portion of the housing to cover the sensor terminal. The first and second protective covers includes attachment portions attached around the front and rear end portions of the housing, respectively. At least one of the attachment portions of the first and second protective covers has a lower hardness than a remaining portion of the protective cover.

Protective covers for gas sensor, gas sensor and gas sensor manufacturing method

A sensor comprising a sensor element, a metallic housing holding therewithin the sensor element, an inner tubular member fixed to an axially rearward end of the metallic housing, and an outer tubular member radially surrounding the inner tubular member and having a radially inward crimping section for contact with an outer surface of the inner tubular member, wherein an axially forward end of the crimping section is disposed axially apart from an axially forward end of the outer tubular member by a distance of 1.5 mm or less.

Sensor

A process for manufacturing a gas sensor, the gas sensor including a gas detecting element, cylindrical metal shell, and cylindrical protector as defined herein, the process comprising: applying a lubricant to an outer circumference of a leading end portion of the metal shell; assembling the metal shell having the lubricant applied thereto and the protector, so that a fitting portion, in which the leading end portion of the metal shell and the protector fit on each other, and a space-forming portion, in which the leading end portion of the metal shell and the protector overlap each other through an annular space, are formed along an axial direction; and welding the metal shell and the protector by forming a welded portion extending from an outer circumference of the protector through the annular space.

Gas sensor manufacturing process, and gas sensor

A gas sensor in which respective terminal leads are fitted and connected to respective electrodes on inner and outer circumferential surface of a hollow, cup-shaped detection element When a leading end connecting portion of a terminal lead () is disposed on the front end side of a separator () and an intermediate portion () extending from the rear end of the leading end connecting portion is inserted into a hole (), a spring tab () provided on the intermediate portion () is pressed against a second wall surface () of the hole (), whereby an engagement portion () is pressed against a first wall surface opposite the second wall surface (). The first projection () is formed on the first wall surface of the hole () so that it can come into contact with and support a first face () of the engagement portion () on opposing lateral sides of the spring tab ().

Gas sensor

It is an object of the invention to provide a sensor which is highly reliable, and a method or producing a sensor which is highly reliable, and which can be easily produced. A method of producing a sensor in which bending of a heater and the like hardly occur is provided. In the invention, an oxygen sensor () has: an oxygen sensor element (); a metal shell (); first and second sensor terminal metal parts (), (); a heater (); heater terminal metal parts (), (); a metal outer tube (); and a separator () which is housed inside the metal outer tube (), in which the terminal metal part () and the like and the heater () are held, and which provides insulation between the terminal metal part () and the like. An outer-tube butting face () is formed in a flange portion () of the separator (). In the metal outer tube (), a flange butting face () which butts against the outer-tube butting face () is formed. Both of the outer-tube butting face () and the flange butting face () form an inclined face which is more radially outward positioned as further advancing toward the tip end. The separator () is pressed toward the rear end. The pressing is conducted by deforming the metal outer tube (), and deforming a pressing metal part () which is placed around a tip end side portion () of the separator ().

Growing community of inventors

Gifu, Japan

Masataka Taguchi