| 摘要 |
PROBLEM TO BE SOLVED: To provide an air-fuel ratio sensor which can effectively restrain condensed water from creeping. SOLUTION: An air-fuel ratio sensor for an internal-combustion engine is provided with an oxygen detection element 10 comprising a gas contact part 11, with a trunk part 41 holding the oxygen detection element 10 and with element covers 31, 32 which comprise opening parts used to introduce an exhaust gas. The element covers 31, 32 are formed as an internal cover situated on the innermost side and as a single or a plurality of external covers. Edge opening parts are formed in the tip face of the internal cover and in tip faces of the respective outer covers. The edge opening parts 22 in the adjacent covers are arranged so as to be dislocated from each other in such a way that the flow passage of the exhaust gas reaching the gas contact part 11 becomes long. It is preferable that a side-face opening part 23 in the internal cover is formed in a part at a distance from the high-temperature part of the gas contact part. |
