Nippondenso Co., Ltd.

Denso Corporation

Masahiro Hamaya

Makoto Hori

Kenji Fukaya

Minoru Ohta

Takashi Kojima

Minoru Ota

Naoto Miwa

Masatoshi Suzuki

Toshimi Miyamoto

Hirokazu Yamada

Isao Watanabe

Hiromi Sano

Syuichi Nakano

Masami Ouki

Nobuyuki Tsuji

Tomoji Fukaya

Yasuhiro Uchida

Tomoyuki Kato

Kazuo Hayashi

Koji Shiozawa

Masato Yamamoto

An oxygen concentration detector comprises a solid electrolyte , a sensing element which consists of the solid electrolyte coated on the surface with an outer electrode , a heater provided inside the solid electrolyte , and a protecting cover which protects the sensing element . The protecting cover has two levels of openings , the outer electrode is constructed within the range defined by the length of the heat-generating part of the heater , and the relationship between the length L of the heat-generating part and the distance between the openings L of the two levels of openings in the axial direction is such that L /L &equals;0.9 to 1.3.

Oxygen concentration detector

An oxygen sensor element is inserted and fixed in a housing. A base body is provided at an end of the housing. The base body is made of a resin. The base body has a flange at an end. The housing has a caulking portion which is deformable when received a pressing force acting in a direction parallel to an axis of the oxygen sensor. By deforming the caulking portion, the flange is tightly connected with the caulking portion.

Oxygen sensor having a solid electrolyte applicable to an internal

An oxygen sensor 3 having a heater 2 capable of providing an improved temperature increasing characteristic, while maintaining an increased amount of introduced air and a high production efficiency. The sensor 3 includes a sensor element 1 having an air chamber 100 in which a heater 2 is arranged. The heater 2 has a rectangular cross sectional shape. In order to produce the heater 2, onto a green ceramic sheet, a heater of a predetermined pattern including a plurality of heater sections is printed. Then, to the printed sheet, different ceramic green sheets are applied so as to obtain a laminated body. The laminated body is subjected to a cutting so as to produce an intermediate body in which a heater section is included. The intermediate body is subjected to a firing to obtain a completed heater.

Oxygen sensor

A lead wire for a sensor has a conductor unit including at least stainless steel wires and copper wires. By setting the cross-sectional percentage of the stainless steel wires in the conductor unit within the range of 30 to 70%, it is possible to obtain a lead wire having low electrical resistance, and high flexibility, tensile strength and elasticity. There are preferred values in hardness and heat treatment of the stainless steel wires. The copper wires are preferably coated with an antioxidant film. The lead wire may include hybrid wires stranded together and obtained by integrally molding or forming stainless steel and copper. It is preferable that the lead wire is coated with an insulating coating material such as a Teflon type resin.

Lead wire for sensor

An oxygen concentration sensor having excellent sealing performance between a lead wire and a lead wire insertion hole includes a sensor element disposed insertedly into a housing, protective covers disposed at an end portion of the housing, lead wires inserted into the protective covers, and an elastic insulating member disposed inside the protective covers and having a lead wire insertion hole for inserting the lead wires. The lead wire insertion hole in the elastic insulating member has a rib protruding in the radial direction. The elastic insulating member is caulked and fixed by the protective covers.

Oxygen concentration sensor

An air-fuel ratio sensor is provided in which sensor lead wires are held by a rubber bush at an end of a sensor housing. The rubber bush is made of a rubber material having a 100% modulus strength equal to or larger than 60 Kgf/cm.sup.2 even after the sensor is used under a temperature environment of 300.degree. C. for 100 hours.

Waterproof structure for an air-fuel ratio sensor

An air fuel ratio sensor has a sensor element having a sensing portion and a flange portion in contact with a tapered portion of an accommodation hole of a housing. The sensor element is hot crimped at a hot crimping portion of a housing. At least the hot crimping portion is made of a ferritic stainless steel formed by cold forging and having a composition content comprising a total amount of C and N impurities of 0.03 wt % or below. The average hot crimping temperature of the housing is performed at lower than 1000.degree. C. as applied for a time period of one second or less.

Air fuel ratio sensor and a method for making the same

An oxygen concentration detector has a detecting element comprising a solid electrolyte inserted into a housing and heating means for heating the detecting element, and the outer surface of the detecting element is provided with a surface layer, the contact angle of the surface layer being larger than the contact angle of the outer surface of the detecting element with which the surface layer directly contacts.

An air-fuel ratio sensor comprises an oxygen concentration sensing element, a housing for holding this oxygen concentration sensing element, and protecting covers with gas holes. The protecting covers comprises an inside cover disposed closely to the oxygen concentration sensing element, and an outside cover surrounding the outside cover. Flange-like peripheral portions, formed on the protecting covers, are fixed to the abutting face of the housing by a caulking operation. These flange-like peripheral portions are disposed alternately along a same closed curve around the oxygen concentration sensing element, so that they are not overlapped with each other.

Air-fuel ratio sensor

A gas sensor includes a sensor element having one end portion exposed to gas to be measured. A plurality of electrodes are provided on the other end portion of the sensor element. A plurality of terminal contacts are resiliently held in electrical contact with the electrodes, respectively, in such a manner that the terminal contacts hold the other end portion of the sensor element therebetween. The electrodes are so provided on the sensor element that the terminal contacts abut against the electrodes to prevent the sensor element from being moved axially and laterally.

Gas sensor

A small-sized highly accurate gas sensor, which is excellent in its reliability of electric connections between contacts and fixtures while being freed from any damage, includes a base member; a detecting unit mounted on the base member for detecting a gas concentration; electrodes mounted on the detecting unit; cylindrical contacts buried integrally in an end portion of the base member; and electric leads interposed between the cylindrical contacts and the electrodes. Contacting fixtures for external lead wires are fitted in and contact the cylindrical contacts so that they are connected to the cylindrical contacts. The cylindrical contacts are formed in their openings with engaging entrances having a smaller diameter than the internal diameter, and the contacting fixtures include elastic contacting portions adapted to be diametrically reduced, when inserted into the cylindrical contacts, than the engaging entrances and expanded, after inserted, to become larger than the engaging entrances and to contact the inner walls of the cylindrical contacts.

Gas sensor having enhanced external connectivity characteristics

An exhaust purification device includes a catalytic converter for purifying exhaust gas from an engine, air-fuel ratio sensors provided on the upstream side and downstream side of the catalytic converter, respectively, for detecting the concentration of a specific component in the exhaust gas, a control device for processing the output of the air-fuel ratio sensors and generating a signal based on the processed output, and a catalyst degradation warning device which operates according to the signal generated by the control device for warning an operator of a degraded catalyst, where the responsiveness of the downstream side air-fuel ratio sensor is lower than the responsiveness of the upstream side air-fuel ratio sensor.

Catalyst degradation detecting apparatus

An oxygen concentration sensor including a solid electrolyte member having two portions, one portion being exposed to a gas of interest and the other portion being exposed to the atmosphere, an inner cover formed with a first space communicating portion arranged to communicate with the other portion of the solid electrolyte member, and a water-proof cover enclosing the inner cover to define a ventilating passage between the inner cover and the water-proof cover and formed with a second space communicating portion maintaining the first space communicating portion of the inner cover in communication with the atmosphere through the ventilating passage. The second space communicating portion of the water-proof cover is axially spaced apart from the first space communicating portion of the inner cover by a predetermined distance. Also included is structure to prohibit the flow of water through said ventilating passage. The second space communicating portion is separated from this structure.

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Anjo, Japan

Masahiro Hamaya