Patent ID: 7178382
Filing Date: 2007-02-20
Classification: G01N

Abstract:
1. A gas sensor comprising: a hollow cylindrical housing having a top end portion and a base end portion; a first porcelain insulator disposed in said housing; a sensor element having a length made up of a sensing portion and a base portion, said sensor element being retained in said housing through said first porcelain insulator; a cylindrical gas cover affixed to the top end portion of said housing to cover the sensing portion of said sensor element; a second porcelain insulator in which the base portion of said sensing element is disposed; a cylindrical air cover covering said second porcelain insulator, said air cover having a length made up of a small-diameter portion, a large-diameter portion, a shoulder formed between the small-diameter portion and the large-diameter portion, and a press-fit end continuing from the large-diameter portion, the small-diameter portion being crimped to retain an elastic insulator therein, the press-fit end being press fit on the base end portion of said housing to make a joint of said air cover to said housing, the large-diameter portion having an inner side wall facing an outer side wall of said second porcelain insulator; and a buffer provided by a clearance between the inner side wall of the large-diameter portion of said air cover and the outer side wall of said second porcelain insulator, the clearance being in a range of 1 to 2.5 mm at a minimum.