Electronic control unit and waterproof case

1. An electronic control unit comprising:

a waterproof case;

a printed-circuit board housed in said waterproof case, said circuit board having electronic components mounted thereon; and

a respiratory filter arranged on said waterproof case for allowing air to flow into and out of the waterproof case; wherein

the waterproof case includes a cover comprising cover walls that are of a uniform thickness;

said cover walls include a raised portion with a depression formed therein;

said depression is laterally delimited by protective walls that extend upward from a base of said depression, and are formed by a portion of the cover walls in the raised portion;

said depression has a polygonal shape defined by said protective walls, and surrounds a portion of the case at which the respiratory filter is arranged;

channels extend through said raised portion in a radial direction from each respective corner of the polygonal shape; and

the respiratory filter is fixable in said depression, in an airtight manner via an O-ring, within a ventilation hole formed so that the hole penetrates through the cover, and an upper extent of each of the protective wall is higher than an upper side of the O-ring.

2. The electronic control unit according to claim 1 , wherein the channels extend radially with respect to the respiratory filter.

3. The electronic control unit according to claim 1 , wherein the channels define open ends that are enlarged, rounded, or both enlarged and rounded.

4. The electronic control unit according to claim 1 , wherein each of the channels is doglegged or labyrinthine in configuration.

5. The electronic control unit according to claim 1 , wherein bottom portions of the channels are provided with inclined walls.

6. The electronic control unit according to claim 1 , wherein:

the protective walls are vertical walls that form side surfaces of the raised portion of the cover walls; and

the channels extend across the raised portion, through the protective walls at one end, and through outer walls of the raised portions at the other end.

7. The electronic control unit according to claim 1 , wherein the polygonal shape is rectangular, and the channels consist of four channels, each of which extends outwardly from one corner of the rectangular polygonal shape.

8. An electronic control unit comprising:

a waterproof case comprising a case body and a cover, said cover being defined by exterior walls, which, when mated with said case body, form said water proof case;

a printed circuit board housed within said waterproof case; and

a respiratory filter arranged on said cover for allowing air to flow into and out of the waterproof case; wherein,

said exterior walls of said cover include a raised portion, and have a uniform wall thickness;

a depression is formed in said raised portion of said cover;

said depression is laterally delimited by raised protective walls which are formed by a portion of said exterior walls that define said cover, and extend upward from a base of said depression;

said respiratory filter is mounted within said depression, in an airtight manner via an O-ring, within a ventilation hole that penetrates through the cover;

channels formed in said raised portion extend radially outward from said depression through said raised portion; and

an upward extent of each of said protective wall is higher than an upper side of said O-ring.

9. The electronic control unit according to claim 8 , wherein:

said depression has a polygonal perimeter with a plurality of corners; and

said channels extend radially outward from each respective corner of said polygonal perimeter.

10. An electronic control unit comprising:

a waterproof case that surrounds a printed circuit board;

a depression formed in a wall of said waterproof case, which wall is of a substantially uniform thickness;

a respiratory filter mounted in said depression;

raised protective walls that form a polygonal planar shaped space and surround said respiratory filter, said protective walls being formed by side walls of said depression that extend substantially perpendicularly to said surface of said waterproof case; and

drainage channels extending radially from said space through the protective walls, the drainage channels extending outwardly in different directions from respective corners of said polygonal planar shaped space.