Ngk Insulators, Inc.

Shodai Hirata

Takayuki Sekiya

Kei Kosaka

Nobukazu Ikoma

Koichi Masuda

Kenji Isaka

Takehiro Koganei

In a gas sensor, not only a tubecovers lead wires, but also the tubecovers an outer peripheral surface of an end portion of an outer cylinderincluding an open end. A portion of the outer peripheral surface of the outer cylindercovered with the tubeis gripped by a clamp. Thus, the clampintegrally grips the tubeand the outer cylinder. Moreover, the tubeprotrudes from the clampto a side of the outer cylinderopposite from the open end(protrusion amount L&#x3e;0). Further, the open endof the outer cylinderforms a large-diameter portion whose outer diameter is larger than an inner diameter Dof the clamp

Insulating grip and apparatus for a gas sensor

An outer tube and a rubber plug are swaged at two sites, a first swaged section located on the side of connections between contact fittings of a connector and leads and a swaged section located closer to an open end of the outer tube than the first swaged section, such that the inside diameter of a portion of the outer tube is greater than the inside diameter. This prevents reduction of the detection accuracy of a gas sensor because sealing properties can be enhanced by heavily swaging at the second swaged section than the first swaged section. Additionally, excessive force can be prevented on the connections and the leads by lightly swaging the first swaged section rather than the second swaged section. Thus, the disconnection between the connector and the leads can be prevented.

Gas sensor

The sensor element, which can detect the concentration of a specified gas, is held with a housing with a front end thereof exposed. A protective cover includes an inner cover and an outer cover, and secured to the housing. A ratio &#x3c6;1/&#x3c6;2 is set to a range from 0.6 to 0.9, where &#x3c6;1 represents an outer diameter of a portion where an inner gas aperture is formed in the inner cover, and &#x3c6;2 represents an inner diameter of a portion where an outer gas aperture is formed in the outer cover.

Gas concentration detection sensor

First outer gas aperturesare arranged in a first cornersuch that the outer opening plane of each first outer gas apertureforms an angle of 45 degrees with a bottom face of a step elementand the outer opening plane forms an angle of 90 degrees with an inner circumferential face of the first outer gas aperture. Second outer gas apertures are arranged in a second corner 146such that the outer opening plane of each second outer gas apertureforms an angle of 45 degrees with a bottom face of an edge sectionand the outer opening plane forms an angle of 90 degrees with an inner circumferential face of the second outer gas aperture. This structure prevents water from adhering to a sensor elementand thereby enhances the response of a gas sensor

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Nagoya, Japan

Shodai Hirata