Denso Corporation

Other

Masato Ozawa

Hirokazu Yamada

Syuichi Nakano

Keiji Kanao

Satoshi Nakamura

Takehito Kimata

Hirofumi Noda

Shota Hagino

Kouji Morita

Hiroshi Sugino

Tomofumi Fujii

Kaneo Buma

Kouichi Hirano

A gas sensor includes a sensor element detecting a concentration of a specified gas, a housing on an inner periphery side of which the sensor element is disposed, a contact terminal contacting an electrode terminal provided to the sensor element, an insulator holding the contact terminal, a base end side cover fixed to a base end side of the housing and covering the insulator, and a disc spring disposed between the cover and the insulator and pushing the insulator toward a tip end side. The insulator has a base end side projecting portion projecting toward the base end side and has an outer periphery base end face, which faces toward the base end side around the base end side projecting portion. The disc spring has a circular body portion and claw portions that project from an inner peripheral edge of the circular body portion toward the base end side.

Gas sensor

A gas sensor is provided with a housing provided with a locking step part formed on an inner peripheral surface thereof; a sensor body provided with a locked flange part locked to the locking step part from a base end side thereof and supported inside the housing; a sealing member filled into a filling part between the inner peripheral surface of the housing and an outer peripheral surface of the sensor body in a base end side of the locked flange part; and an insulation member provided between the inner peripheral surface of the housing and the outer peripheral surface of the sensor body in a base end side of the sealing member. The filling part includes an annular groove protruding in an outer peripheral side.

A gas sensor includes a sensor element, a housing, a contact terminal, a second insulator, a lead wire, a sealing member, an inner periphery side cover and an outer periphery side cover. The inner periphery side cover is mounted on an outer periphery at a position on a base end side in an axial direction of the housing. The outer periphery side cover is disposed on the outer periphery side of the inner periphery side cover, forms a substantially cylindrical space with the inner periphery side cover and holds the sealing member on an inner periphery side.

A gas sensor includes a sensor element, spring terminals, and a spring insulator. The spring terminals are formed of bendable wire. The spring insulator includes an insertion hole in which a proximal section of the sensor element is inserted and retaining grooves, which communicate with the insertion hole. The spring terminals each include a holding section retained in the associated retaining groove and an arm section, which extends from the holding section and comes into contact with the associated one of terminal contact portions of the sensor element while flexing with respect to the holding section. When viewed in an insertion direction of the sensor element to the insertion hole, a flexing direction of the arm section of each spring terminal with respect to the holding section is inclined with respect to the outer surface of the associated terminal contact portion.

The gas sensor includes a sensor element having electrode pads formed in its electrode forming surfaces at the proximal end portion thereof, an insert-holding insulator insert-holding the sensor element, a housing insert-holding the insert-holding insulator, and a terminal unit. The proximal end portion of the sensor element is held by the terminal unit which includes a pair of proximal end insulators formed with metal terminals at their inner surfaces, and a spring member pressing the proximal end insulators in a direction that they approach each other. Each of the proximal end insulators includes an insulator contact portion in contact with one of the electrode forming surfaces. The insulator contact portion is located closer to the proximal end of the sensor element than a terminal contact portion at which the metal terminal contacts a corresponding one of the electrode pads.

Gas sensor and method of manufacturing same

An improved manufacturing method for a gas sensor is provided which is capable of establishing a required hermetic seal in a body of the gas sensor. The method includes preparing a sensor assembly including a housing, an air cover, an insulation porcelain, and a sensor element, pressing the air cover against the housing to fit an end of the air cover on an end of the housing to form an overlap thereof, and welding the air cover to the housing over the overlap. The welding is accomplished while pressing the air cover against the housing, thereby compressing an elastic member in the air cover to establish a hermetic seal between the sensor element and the housing.

Gas sensor manufacturing method

Method of manufacturing a gas sensor

A gas sensing element is placed in an element insertion hole of an insulator. The element insertion hole consists of a larger-diameter portion and a smaller-diameter portion. A clearance between an inner surface of the larger-diameter portion and an outer surface of the gas sensing element is filled with a sealing material. A clearance between an inner surface of the smaller-diameter portion and the outer surface of the gas sensing element is filled with a cushion filler having the capability of withstanding a loading force ranging from 5N to 1,000N.

An improved manufacturing method for a gas sensor is provided which is capable of establishing a required hermetic seal in a body of the gas sensor. The method includes preparing a sensor assembly including a housing, an air cover, an insulation porcelain, and a sensor element, pressing the air cover against the housing to fit an end of the air cover on an end of the housing to form an overlap thereof, and welding the air cover to the housing over the overlap. The welding is accomplished while pressing the air cover against the housing, thereby compressing an elastic member in the air cover to establish a hermetic seal between the sensor element and the housing. The air cover may be tack welded to the housing before welding the overlap for securing a positional relation between the air cover and the housing.

A gas sensor element is inserted into a housing having a base end and is fixed with respect to the housing. Terminal electrodes are provided on the base end of the sensor element. An atmosphere-side cover including an insulator with terminal accommodation holes is provided on the base end of the housing. The insulator also has an element accommodation hole (communicating with the terminal accommodation holes) in which the base end of the sensor element is placed. The insulator has ribs forming inner surfaces defining the element accommodation hole. The rib thickness is smaller than that of the sensor element base end. Metal terminals are at least partially placed in respective terminal accommodation holes and have connecting portions with leads for external electrical connection. The ribs are located between the metal terminals to form spaces between the metal terminals. As the sensor element base end is placed in the element accommodation hole, terminal electrodes on the base end come into contact with the metal terminals and thereby electrically connected with the leads.

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Toyota, Japan

Masato Ozawa