Ventilation structure and ventilation member

1. A ventilation structure comprising:

a housing having an opening portion; and

a ventilation member formed of a porous resin and attached to the housing so as to cover the opening portion, the ventilation member comprising a tubular portion, a first wall forming the tubular portion being configured so as to allow gas to pass through the first wall by passing through the pores of the porous resin of the first wall, wherein

the ventilation member is fitted to a side surface of a wall portion of the housing facing the opening portion or to a side surface of a projecting portion provided on an outer surface of the wall portion, with at least one of the wall portion, the projecting portion, and the ventilation member being elastically deformed.

2. The ventilation structure according to claim 1 , wherein

the ventilation member comprises: a recessed portion having an opening; and a side wall portion defining a side surface of the recessed portion, and

the side wall portion is fitted to the side surface of the projecting portion, with at least one of the projecting portion and the side wall portion being elastically deformed.

3. The ventilation structure according to claim 2 , wherein a side surface of the side wall portion has a contact surface that is in contact with the side surface of the projecting portion and a non-contact surface that is not in contact with the side surface of the projecting portion.

4. The ventilation structure according to claim 1 , wherein

the ventilation member comprises: a fitting portion fitted in the opening portion; and a flange portion formed integrally with the fitting portion and having an outer diameter greater than an outer diameter of the fitting portion, and

the fitting portion is fitted to the side surface facing the opening portion, with at least one of the wall portion and the fitting portion being elastically deformed.

5. The ventilation structure according to claim 4 , wherein

the fitting portion comprises: a through hole; and a first wall portion formed to surround the through hole and having an inner surface facing the through hole and an outer surface opposite to the inner surface, the first wall portion being configured to allow a gas to pass through between the inner surface and the outer surface, and

the flange portion comprises: a recessed portion communicating with the through hole; and a second wall portion formed to surround the recessed portion and having an inner surface facing the recessed portion and an outer surface opposite to the inner surface, the second wall portion being configured to allow a gas to pass through between the inner surface and the outer surface.

6. The ventilation structure according to claim 1 , wherein a surface of the ventilation member is subjected to liquid-repellent treatment.

7. The ventilation structure according to claim 1 , wherein the porous resin is a porous molded body composed of resin fine particles that are bound together.

8. The ventilation structure according to claim 1 , wherein the ventilation member has a thickness of 0.2 mm or more and 20 mm or less.

9. The ventilation structure according to claim 1 , wherein the porous resin has a porosity of 20% or more and 90% or less.

10. A ventilation member adapted to be attached to a housing so as to cover an opening portion of the housing, the ventilation member being formed of a porous resin and comprising a contact surface, the ventilation member comprising a tubular portion, a first wall forming the tubular portion being configured so as to allow gas to pass through the first wall by passing through the pores of the porous resin of the first wall, wherein

when the ventilation member is attached to the housing so as to cover the opening portion, the contact surface is in contact with a side surface of a wall portion of the housing facing the opening portion or with a side surface of a projecting portion provided on an outer surface of the wall portion, with at least one of the wall portion, the projecting portion, and the ventilation member being elastically deformed.

11. The ventilation member according to claim 10 , comprising: a recessed portion having an opening; and a side wall portion defining a side surface of the recessed portion, wherein

the side wall portion has the contact surface, and

when the ventilation member is attached to the housing so as to cover the opening portion, the contact surface is in contact with the side surface of the projecting portion, with at least one of the projecting portion and the side wall portion being elastically deformed.

12. The ventilation member according to claim 10 , comprising: a fitting portion adapted to be fitted in the opening portion; and a flange portion formed integrally with the fitting portion and having an outer diameter greater than an outer diameter of the fitting portion, wherein

the fitting portion has the contact surface, and

when the ventilation member is attached to the housing so as to cover the opening portion, the contact surface is in contact with the side surface facing the opening portion, with at least one of the wall portion and the fitting portion being elastically deformed.

13. The ventilation member according to claim 10 , wherein the porous resin is a porous molded body composed of resin fine particles that are bound together.

14. The ventilation member according to claim 10 , wherein the ventilation member has a thickness of 0.2 mm or more and 20 mm or less.

15. The ventilation member according to claim 10 , wherein the porous resin has a porosity of 20% or more and 90% or less.

16. The ventilation structure according to claim 1 , wherein

the ventilation member comprises a bottom portion, a second wall forming the bottom portion being configured so as to allow gas to pass through the second wall by passing through the pores of the porous resin of the second wall, and

the tubular portion and the bottom portion are formed integrally.

17. The ventilation member according to claim 10 , wherein

the ventilation member comprises a bottom portion, a second wall forming the bottom portion being configured so as to allow gas to pass through the second wall by passing through the pores of the porous resin of the second wall, and

the tubular portion and the bottom portion are formed integrally.