Abstract: In a gas sensor, not only a tube 70 covers lead wires 48, but also the tube 70 covers an outer peripheral surface of an end portion of an outer cylinder 46 including an open end 46a. A portion of the outer peripheral surface of the outer cylinder 46 covered with the tube 70 is gripped by a clamp 80. Thus, the clamp 80 integrally grips the tube 70 and the outer cylinder 46. Moreover, the tube 70 protrudes from the clamp 80 to a side of the outer cylinder 46 opposite from the open end 46a (protrusion amount L>0). Further, the open end 46a of the outer cylinder 46 forms a large-diameter portion whose outer diameter is larger than an inner diameter D1 of the clamp 80.

Abstract: 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.

Abstract: In a gas sensor, not only a tube 70 covers lead wires 48, but also the tube 70 covers an outer peripheral surface of an end portion of an outer cylinder 46 including an open end 46a. A portion of the outer peripheral surface of the outer cylinder 46 covered with the tube 70 is gripped by a clamp 80. Thus, the clamp 80 integrally grips the tube 70 and the outer cylinder 46. Moreover, the tube 70 protrudes from the clamp 80 to a side of the outer cylinder 46 opposite from the open end 46a (protrusion amount L>0). Further, the open end 46a of the outer cylinder 46 forms a large-diameter portion whose outer diameter is larger than an inner diameter D1 of the clamp 80.

Abstract: 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.

Abstract: 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 ?1/?2 is set to a range from 0.6 to 0.9, where ?1 represents an outer diameter of a portion where an inner gas aperture is formed in the inner cover, and ?2 represents an inner diameter of a portion where an outer gas aperture is formed in the outer cover.

Abstract: First outer gas apertures 144a are arranged in a first corner 144b such that the outer opening plane of each first outer gas aperture 144a forms an angle of 45 degrees with a bottom face of a step element 145 and the outer opening plane forms an angle of 90 degrees with an inner circumferential face of the first outer gas aperture 144a. Second outer gas apertures are arranged in a second corner 146b such that the outer opening plane of each second outer gas aperture 146a forms an angle of 45 degrees with a bottom face of an edge section 146 and the outer opening plane forms an angle of 90 degrees with an inner circumferential face of the second outer gas aperture 146a. This structure prevents water from adhering to a sensor element 110 and thereby enhances the response of a gas sensor 110.

Abstract: The sensor element 110, which can detect the concentration of a specified gas, is held with a housing 102 with a front end thereof exposed. A protective cover 120 includes an inner cover 130 and an outer cover 140, and secured to the housing 102. A ratio ?1/?2 is set to a range from 0.6 to 0.9, where ?1 represents an outer diameter of a portion where an inner gas aperture 134a is formed in the inner cover 130, and ?2 represents an inner diameter of a portion where an outer gas aperture 144a is formed in the outer cover 140.

Abstract: First outer gas apertures 144a are arranged in a first corner 144b such that the outer opening plane of each first outer gas aperture 144a forms an angle of 45 degrees with a bottom face of a step element 145 and the outer opening plane forms an angle of 90 degrees with an inner circumferential face of the first outer gas aperture 144a. Second outer gas apertures are arranged in a second corner 146b such that the outer opening plane of each second outer gas aperture 146a forms an angle of 45 degrees with a bottom face of an edge section 146 and the outer opening plane forms an angle of 90 degrees with an inner circumferential face of the second outer gas aperture 146a. This structure prevents water from adhering to a sensor element 110 and thereby enhances the response of a gas sensor 110.