HUMIDITY DETECTION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a humidity detection device for an internal combustion engine capable of suppressing secular deterioration of a sensor element and lengthening the service life of the sensor element by a simple and inexpensive constitution, and thereby attaining improvement of detection accuracy and reduction of cost.

SOLUTION: This humidity detection device 1 absorbs HC and moisture in exhaust gas flowing in a bypass exhaust passage 5 by a HC absorbent 22 provided in the bypass exhaust passage 5 joining in a main exhaust passage 4 connected to the internal combustion engine 2 after branching from the passage 4. The device 1 is provided with a humidity sensor 10 having a detecting part 14 provided on an upstream side of the HC absorbent 22 and including the sensor element 12 for detecting relative humidity VHUM within the bypass exhaust passage 5 and a cover 15 for covering the detecting part 14 from the upstream side to prevent hitting of exhaust gas flowing in the bypass exhaust passage 5 on the detecting part 14 from the upstream side of the humidity sensor 10.

COPYRIGHT: (C)2003,JPO