Structure of gas sensor ensuring high degree of gas-tight seal
AssigneeDenso Corporation
InventorNobuyuki Tsuji
Life of this patent
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Abstract
An improved structure of a gas sensor is provided which is designed for achieving desired crimping of an end portion of a sensor housing to establish a higher degree of gas-tight seal between the housing and a sensor element. The sensor element is fitted within the sensor housing. The end portion of the sensor housing is crimped or bent to urge the sensor element into constant abutment with an inner wall of the housing through a sealing member. The housing has an unique shape and dimensions selected to ensure the higher degree of gas-tight seal regardless of the degree of wear of a crimper and/or dimensional error of the housing.
Claims5
A gas sensor comprising:
- a hollow cylindrical housing having a length with a first and a second end portion opposed to each other;
- a sensor element fitted within said hollow cylindrical housing, said sensor element having formed therein a reference gas chamber;
- a measurement gas-exposed cover joined to the first end portion of said hollow cylindrical housing, said measurement gas-exposed cover having defined therein a measurement gas chamber into which a gas to be measured by said sensor element is admitted and to which said sensor element is exposed;
- a reference gas-exposed cover joined to the second end portion of said hollow cylindrical housing, said reference gas-exposed cover having defined therein a reference gas chamber into which a reference gas is admitted and which leads to the reference gas chamber of said sensor element;
- a sealing member disposed between the first end portion of said hollow cylindrical housing and said sensor element;
- and
- an annular end portion formed at the first end portion of said hollow cylindrical housing, said annular end portion including an annular neck and an annular extension which extends from the annular neck toward a tip end of the first end portion and is greater in outer diameter than the annular neck, the annular extension being crimped to urge said sensor element into constant abutment with said hollow cylindrical housing through said sealing member to establish a gas-tight seal between the reference gas chamber of said reference gas-exposed cover and the measurement gas chamber, the annular extension before being crimped having a shape including an annular tapered portion having an outer diameter decreasing toward the tip end of the first end portion and an annular straight portion extending straight from the annular tapered portion toward the tip end of said first end portion, the annular straight portion being bent inwardly of said hollow cylindrical housing to urge said sensor element into constant abutment with said hollow cylindrical housing.
Dependencies are inferred from the claim text.