Structure of gas sensor designed to minimize damage to porcelain insulators
AssigneeDenso Corporation
InventorsYasuyuki Satou, Seiji Maeda
Life of this patent
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Abstract
A gas sensor made up of a sensor element and a first and a second hollow cylindrical porcelain insulators covering the sensor element. The first porcelain insulator is laid on the second porcelain insulator in alignment within a body of the gas sensor. A base end surface of the first porcelain insulator is placed in abutment with a top end surface of the second porcelain insulator. At least one of the base end surface of the top end surface has a ground flat area which forms an interface between the first and second porcelain insulators without micro-contacts resulting in concentration of local stress which would lead to breakage of the first or second porcelain insulator when subjected to physical loads.
Claims5
A gas sensor comprising:
- a hollow cylindrical housing;
- a sensor element including a sensing portion and a base portion, said sensing portion working to produce a signal as a function of concentration of a target component of gases;
- a first porcelain insulator having a top end surface and a base end surface opposed to the top end surface, said first porcelain insulator being installed in said housing and through and having said sensor element pass therethrough to expose the sensing portion to the gases outside the top end surface of said housing;
- a second porcelain insulator having a top end surface and a base end surface opposed to the top end surface, said second porcelain insulator being aligned with said first porcelain insulator in abutment of the top end surface thereof with the base end surface of said first porcelain insulator;
- and
- a ground flat area formed on at least one of the base end surface of said first porcelain insulator and the top end surface of said second porcelain insulator to define an area of contact between the base end surface of said first porcelain insulator and the top end surface of said second porcelain insulator.
Dependencies are inferred from the claim text.