Ventilation member and vented housing using the same

1. A ventilation member comprising:

a breathable film transmitting gas passing through an opening portion of a housing in a state in which said breathable film is fixed to said opening portion; and

a support including a supporting portion for supporting said breathable film and an insertion portion to be inserted into said opening portion of said housing;

wherein a lock structure for locking said support in said housing by rotating said support around a central axis of said support is formed in said insertion portion; and

wherein said breathable film is one of a fluororesin porous material and a polyolefin porous material and said breathable film has been subjected to a liquid-repellent treatment with a polymer having a perfluoro alkyl group.

2. A ventilation member according to claim 1 , wherein said lock structure is of a spiral groove formed in an outer circumference of said insertion portion.

3. A ventilation member according to claim 1 , wherein said lock structure is of at least one protrusion portion formed in an outer circumference of an insertion-start-side end portion of said insertion portion.

4. A ventilation member according to claim 1 , wherein a through hole is formed in said support, and said breathable film is fixedly attached to said supporting portion so as to cover said through hole.

5. A ventilation member according to claim 1 , wherein a plurality of through holes are formed in a surface of said support covered with said breathable film.

6. A ventilation member according to claim 1 , wherein said support includes a seal portion on a surface of said supporting portion facing said housing.

7. A ventilation member according to claim 1 , wherein said support includes a protective portion covering at least a part of said breathable film from above of said breathable film.

8. A ventilation member according to claim 1 , wherein said support has an outer shape selected from a circular shape and a polygonal shape when said support is observed in a gas permeable direction.

9. A ventilation member according to claim 1 , wherein said support has an engagement structure with which a tool can be engaged.

10. A ventilation member according to claim 9 , wherein said engagement structure includes at least one kind selected from a convex portion and a concave portion.

11. A ventilation member according to claim 9 , wherein said engagement structure is formed in at least one surface selected from a surface of said support which can be viewed when said support is observed in a gas permeable direction from outside of said housing, and an outer circumferential surface of said support.

12. A ventilation member according to claim 1 , wherein a reinforcement material is laminated to said breathable film.

13. A vented housing comprising a ventilation member according to claim 1 , which is fixed to said opening portion of said housing.

14. A ventilation member, comprising:

a breathable film transmitting gas passing through an opening portion of a housing in a state in which said breathable film is fixed to said opening portion; and

a support including a supporting portion for supporting said breathable film, and an insertion portion to be inserted into said opening portion of said housing, and having a columnar shape whose diameter is substantially the same as that of said opening portion of said housing, and at least one protrusion portion formed in an outer circumference of an insertion-start-side end portion of said insertion portion, said at least one protrusion portion being formed in a shape corresponding to said opening portion of said housing;

wherein said support is locked in said housing by rotating said support around a central axis of said support.