Ngk Spark Plug Company, Limited

Yasuhiro Fujita

Takayoshi Atsumi

Masataka Taguchi

Yoshiaki Matsubara

Takahiro Hayashi

Hitoshi Iimi

Mitsuru Sugihara

Hiromichi Hayashi

Daisuke Miyata

Yuji Shimazaki

Tetsuma Shimozato

Hidekazu Kato

Daiki Tabuchi

Chihiro Seki

Makoto Togawa

A gas sensor includes a metal shell, a gas sensor element held in the metal shell, a metal portion arranged between a flange portion of the gas sensor element and a seat portion of the metal shell and a porous thermal spray layer formed on the gas sensor element. When viewed in cross section along the direction of an axis of the gas sensor, a corner of the metal portion axially overlaps in position with or radially outwardly protrudes from an outer surface of a part of the thermal spray layer located on a side surface of the flange portion and is brought into contact with the seat portion. A rear end-facing surface of the metal portion is brought into contact with an outer surface of the thermal spray layer at a position radially inside the side surface of the flange portion.

Gas sensor

A protector has a two-stage structure that includes a large-diameter portion and a small-diameter portion. The large-diameter portion includes a cylindrical first peripheral wall and a first front end wall. The small-diameter portion includes a cylindrical second peripheral wall connected to the first front end wall and a second front end wall connected to a front end portion of the second peripheral wall. Opening portions are not formed in the first and second peripheral walls. First opening portions, which are opened toward only first recessed portions and an inner surface of the first peripheral wall, are formed at the first front end wall. A second recessed portion and second opening portions, which are formed in the second recessed portion and are opened toward an inner surface of the second peripheral wall, are formed in the second front end wall.

A gas sensor suppresses the deterioration of gas tightness caused by failure of a sealing material. The gas sensor includes: a housing; a sensor element arranged inside the housing; a sealing material filling a gap between the sensor element and the housing; an insulation member arranged on a proximal end side of the sealing material; and an annular metal ring arranged on a proximal end side of the insulation member. The sealing material, the insulation member and the metal ring are fixed under pressure by caulking from a proximal end side to a distal. A proximal-end facing surface of an inner peripheral portion of the metal ring is spaced apart from the caulking portion in an opposing region where an inner end of the caulking portion and the metal ring face each other in an opposed manner.

A gas sensor, including a cylindrical outer tube; and a seal member disposed in the outer tube, the seal member including: a lead wire insert hole and an atmosphere communication hole extending in an axial direction thereof. The gas sensor further includes: a protection portion which covers the atmosphere communication hole from the rear end of the gas sensor in the axial direction, the protection portion having a protrusion which protrudes toward a rear side of the gas sensor, and has an opening smaller than an opening of the atmosphere communication hole, wherein the protrusion is disposed at a further front end side of the rear end surface of the seal member.

A gas sensor, including a cylindrical outer tube; and a seal member disposed therein, the seal member including: a lead wire insert hole and an atmosphere communication hole. The seal member has a groove extending outwards in a radial direction at a rear end-facing surface from the atmosphere communication hole while circumventing the lead wire insert hole, the groove having a cutout toward the front end of the seal member. The gas sensor further includes: a protection portion which covers the atmosphere communication hole; and an arm couples the protection portion and the outer tube, and extends in the radial direction, the arm being at least partially disposed in the groove of the seal member. and the arm is disposed so as to define a gap with the bottom surface of the groove.

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 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 ().

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 ().

Sensor, sensor producing method, and assembly of separator and urging member

A gas sensor includes a detection element for detecting a gas component of a gas to be measured, a casing for holding the detection element and a seal member forming a reference gas space together with the casing. The seal member has an end surface exposed to the atmosphere and a through-hole for establishing communication between the atmosphere and the reference gas space. A cylindrical insert member is inserted in the through-hole of the seal member. A sheetlike air permeable filter is sandwiched between an inner surface of the through-hole of the seal member and the cylindrical insert member so as to cover an atmosphere side opening portion of the cylindrical insert member. The atmosphere side opening portion of the cylindrical insert member is retracted from the end surface of the seal member toward the interior of the through-hole, whereby an atmosphere side face of the air permeable filter is retracted from the end surface of the seal member.

Growing community of inventors

Kaizu, Japan

Yasuhiro Fujita