Ngk Spark Plug Company, Limited

Daisuke Tahira

Shingo Ito

Yuichi Yamada

Makoto Kume

Keiichi Noda

Takehiro Oba

Atsunori Okada

Katsuki Aoi

Nobuhiro Inoue

A gas sensor () includes a sensor element (), a metallic shell (), a powder filler member (), a first ceramic holder () in contact with the rear end of the powder filler member and from which the sensor element protrudes, and a second ceramic holder () in contact with the forward end of the powder filler member and from which the sensor element protrudes. The powder filler member has a higher thermal expansion coefficient than that of the first and second ceramic holders. The first ceramic holder, powder filler member, and second ceramic holder are pressed by force application means (). A relation 0.40&#x3c;(L&#x2212;M)/L&#x3c;0.58 holds, where L is the axial distance between the rearward-facing surface of the first ceramic holder and the forward end of the second ceramic holder, and M is the axial length of the powder filler member.

Gas sensor

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 having a metal shell, a holder placed in the metal shell and a sensor element inserted through an axial insertion hole of the holder. The holder has a recessed portion recessed toward the rear from a front end face of the 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 of the porous protection layer is situated within the recessed portion of the holder and is located at the rear side with respect to the front end face of the holder while maintaining a space between an inner circumferential surface of the recessed portion and an outer circumferential surface of the porous protection layer.

A gas sensor () has a platelike detection element () extending in an axial direction and a ceramic member () having an element insertion hole () into which the detection element () is inserted. When the ceramic member () is viewed from the axial direction, the element insertion hole () has a main insertion hole () having a substantially quadrate shape surrounded by four sides, and relief holes (), (), () and (), each of which is surrounded by an outline connecting ends of two adjacent sides of the four sides of the main insertion hole () and located radially outward of the main insertion hole () so as to communicate with the main insertion hole

A protector () is inserted into a metallic shell () such that at least a portion of each gas introduction hole () is located on the base end side with respect to the forward end () of the metallic shell. The metallic shell has a gas introduction space Sdefined by a forward-end-side inner surface () of the metallic shell and an outer surface () of the protector and which guides a gas-to-be-detected (exhaust gas G) from a region on the forward end side of the metallic shell into the gas introduction holes of the protector. The base end of the forward end portion () of the detection element () is located on the base end side with respect to the forward end () of each gas introduction hole, and the forward end of the forward end portion is located on the forward end side with respect to the base end () of each gas introduction hole.

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.

A knocking sensor which includes: a piezoelectric element; a support member having a support body portion, the support body portion including a support surface directly or indirectly supporting the piezoelectric element; and a resin coating covering the piezoelectric element and at least a part of the support member, the resin coating having an outside portion covering an outer circumference of the piezoelectric element and an outer circumference of the support body portion. The support body portion of the support member has a first engagement portion on the base end side thereof. The resin coating has a curved portion which extends from the outside portion toward the interfacial direction inner side, and curves toward the base end side of the support body portion. Further, the curved portion includes a second engagement portion which engages the first engagement portion.

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Komaki, Japan

Daisuke Tahira