| 摘要 |
<p>PROBLEM TO BE SOLVED: To secure breathing function through a ventilation film. SOLUTION: A protective wall 12 is stood on one side face 11 of a casing 10, a vent 15 is opened in the rear surface thereof and a ventilation film 25 is applied to the surface of the vent 15 and then secured by welding a retaining member 30. The retaining member 30 has such a structure as a hood 40 is provided on the surface of an annular substrate 31. A regulating part 52 is disposed in the hood 40 with a ventilation path 57 being provided around the regulating part 52. An auxiliary vent 50 is made in the lower wall of the hood 40 in correspondence with the upper part of a cut groove 21 made in the lower wall of the protective wall 12. Water or oil intruding into the hood 40 is thereby discharged from the auxiliary vent 50 to the outside through the cut groove 21. Even if grease adheres to the ventilation path 57 to block the ventilation path 57, breathing can be performed through the ventilation film 25 utilizing the auxiliary vent 50.</p> |
