Denso Corporation

Masatake Nakamura

Kazutoshi Koie

Kengo Toguchi

Junji Moriwaki

A gas sensor includes a solid electrolyte body provided with a measured gas side electrode and a reference gas side electrode, a heater in the solid electrolyte body, a housing for holding the solid electrolyte body therein, and a cover for covering the solid electrolyte body. The cover has a large-diameter cover portion positioned on an outer circumferential side of the solid electrolyte body, a small-diameter cover portion positioned adjacent to a tip side of the large-diameter cover portion and formed smaller than the large-diameter cover portion, and a stepped portion connecting the small-diameter cover portion and the large-diameter cover portion. A first through hole is formed at a tip of the small-diameter cover portion. A second through hole is formed at a plurality of positions in a circumferential direction of the stepped portion.

Gas sensor

A gas sensor includes a housing, an insulator, an inner cover, and an outer cover. An inner peripheral hole of the housing includes a rear end side hole and a front end side hole portion and a rear end side hole portion. A step portion which is formed in a slant shape is provided at a boundary between the front end side hole portion and the rear end side hole portion. The inner cover has a large-diameter portion which faces the step portion. The insulator has a flange which holds the large-diameter portion between itself and the step portion. A burr is formed on the surface of the large-diameter portion. The burr faces the surface of the step portion. This avoids inclination of the cover relative to the inner peripheral hole of the housing and obviates the risk of damage to or breakage of a device body.

A gas sensor includes a sensor device, a device-side insulator porcelain, an atmospheric side insulator porcelain, a housing, a seal disposed between the housing and the device-side insulator porcelain, and an atmospheric side cover. The atmospheric side cover includes a large-diameter portion, a small-diameter portion, and a shoulder portion formed therebetween. The shoulder portion presses a base end surface of the atmospheric side insulator porcelain to a front end side through a biasing member to place the atmospheric side insulator porcelain in contact with the device-side insulator porcelain. The shoulder portion is defined by a contact portion placed in contact with the biasing member and a detached portion separate from the biasing member to form a communication path which communicates between an outer space and an outside path. This avoids entry of measurement gas into an air atmosphere within the atmospheric side insulator porcelain to obtain correct sensor outputs, also avoids breakage of the atmospheric side insulator porcelain, and reduces the manufacturing costs.

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Kariya, Japan

Masatake Nakamura