OXYGEN SENSOR AND OXYGEN SENSOR CONTROL DEVICE

摘要

The present invention provides an EMF type oxygen sensor which is arranged in the exhaust path of an internal combustion engine and is subjected to activation treatment in which unidirectional voltage is applied between an atmosphere pole and an exhaust pole of the oxygen sensor. In the case of a control device for controlling an oxygen sensor in which voltage is applied with the atmosphere pole being positive, unidirectional voltage is additionally applied between the atmosphere pole and exhaust pole during use of the oxygen sensor (2) to make the atmosphere pole positive and the exhaust pole negative, for example when the oxygen sensor is employed in an environment in which the air/fuel ratio of the internal combustion engine is enriched with respect to the theoretical air/fuel ratio. In contrast,in the case of a control device for controlling an oxygen sensor in which voltage is applied that makes the atmosphere pole negative and the exhaust pole positive, unidirectional voltage is applied between the atmosphere pole and exhaust pole during use of the oxygen sensor (2), to make the atmosphere pole negative and the exhaust pole positive, for example when the oxygen sensor is employed in an environment in which the air/fuel ratio is lean with respect to the theoretical air/fuel ratio.