| 摘要 |
PROBLEM TO BE SOLVED: To ensure a flow rate to a gas sensor even when the whole of a filter is wet and to ensure removing performance (filter performance) for refuse and dust. SOLUTION: An air intake is opened at the lower part of the front of a case 1 and meanwhile, an air discharge port 1d is opened to the upper part of the rear of the case 1. An air passage 13 through which air flows from the air intake to an air outlet is formed in the case 1. Filters 2a and 2b are arranged in a state to interrupt an air passage 13, and a gas sensor 3 is arranged in a position situated downstream from the filters 2a and 2b of the air passage 13. A bypass passage 14 having one end opened to the end face on the upper stream side of the air passage 13 and the other end opened to the end face on the downstream side of the air passage 13 is formed in the filters 2a and 2b obliquely to a flow (a) of air in the air passage 13.
|
