Ventilation member
The ventilation member of the present invention includes: a support having a through hole serving as a part of an air passage between an interior space and an exterior space of a housing when the support is attached to an opening of the housing; an air-permeable membrane disposed on the support to cover one end of the through hole that opens into the exterior space; and a cover member covering the support over the air-permeable membrane so as to form, between the cover member and the support, a ventilation space serving as a part of the air passage. The support includes a first oil-repellent portion formed around the air-permeable membrane. The first oil-repellent portion is formed by oil-repellent treatment of a part of a first surface of the support. The present invention provides a ventilation member suitable for preventing adhesion of oil to the air-permeable membrane even if the oil enters the inside of the cover member.
1. A ventilation member attachable to an opening of a housing, the ventilation member comprising:
a support having a through hole serving as a part of an air passage between an interior space and an exterior space of the housing when the support is attached to the opening;
an air-permeable membrane disposed on the support so as to cover one end of the through hole that opens into the exterior space; and
a cover member covering the support over the air-permeable membrane so as to form, between the cover member and the support, a ventilation space serving as a part of the air passage,
wherein the support comprises:
a first oil-repellent portion formed around the air-permeable membrane, the first oil-repellent portion being formed by an oil-repellent treatment of a part of a first surface of the support; and
a second oil-repellent portion formed around an end of the through hole that opens into the interior space, opposite to the one end thereof opening to the exterior space, the second oil-repellent portion being formed by an oil-repellent treatment of a part of a second surface of the support.
2. The ventilation member according to claim 1 , wherein the first oil-repellent portion is formed along an outer edge of the air-permeable membrane.
3. The ventilation member according to claim 1 , wherein the first oil-repellent portion has a ring shape.
4. The ventilation member according to claim 1 , wherein the support further comprises third oil-repellent portions formed around the first oil-repellent portion such that the third oil-repellent portions are spaced apart from each other, the third oil-repellent portions being formed by an oil-repellent treatment of a part of the first surface of the support.
5. The ventilation member according to claim 4 , wherein
the cover member has an aperture in a side wall of the cover member, the aperture communicating the ventilation space with the exterior space, and
the third oil-repellent portions are formed so as to be exposed to the aperture of the cover member.
6. The ventilation member according to claim 4 , wherein the third oil-repellent portions each have an arc shape.
7. The ventilation member according to claim 1 , wherein the support further comprises fourth oil-repellent portions formed around the third oil-repellent portion such that the fourth oil-repellent portions are spaced apart from each other, the fourth oil-repellent portions being formed by an oil-repellent treatment of a part of the second surface of the support.
8. The ventilation member according to claim 1 , wherein the ventilation member further comprises a sealing member disposed between the second surface of the support and the housing.