Waterproof structure for connector

1. A waterproof structure for a connector which prevents that water is infiltrated into openings of terminal accommodating cavities which are respectively formed in a pair of housings fitted to each other, wherein

one of the pair of the housings includes:

a base part formed with the terminal accommodating cavity;

a hood part protruding forward from the base part; and

an annular member having a cylindrical shape and protruding forward to surround the opening at an inner side of the hood part from a circumferential edge of the opening formed at a front end surface of the base part surrounded by the hood part, the annular member being separated from and extending within the hood part with a space formed therebetween,

the other of the pair of the housings includes:

a base part formed to have a similar shape to an inner circumferential surface of the hood part and formed with the terminal accommodating cavity; and

an annular member having a cylindrical shape and protruding forward to surround the opening from a circumferential edge of the opening formed at a front end surface of the base part,

the annular member of one housing being inserted into an annulus of the annular member of the other housing at a time of fitting, and

at least one of the annular members includes a protrusion part which is an annular protrusion part protruding toward the other annular member and has a top part which is pressed by a surface of the other annular member at the time of fitting,

wherein the at least one of the annular members is expanded into the space to overlap the other annular member without pressing against the hood part.

2. The waterproof structure for a connector according to claim 1 , wherein

the protrusion part is formed such that a sectional shape of the top part in a cross section orthogonal to a circumferential direction of the annular member is an arc shape.

3. The waterproof structure for a connector according to claim 1 , wherein

the protrusion part includes a tilted surface which is tilted from the top part toward a protruding end of the annular member.

4. The waterproof structure for a connector according to claim 1 , wherein

an inner circumferential surface of one annular member is formed with the protrusion part as an annular first protrusion part which protrudes to contact an outer circumferential surface of the other annular member,

the outer circumferential surface of the other annular member is formed with an annular second protrusion part which protrudes to contact the inner circumferential surface of the one annular member, and

the first protrusion part and the second protrusion part are arranged to be deviated from each other at the time of fitting.

5. The waterproof structure for a connector according to claim 4 , wherein

any one of the first protrusion part and the second protrusion part has a shape which regulates movement of the other in a fitting release direction at the time of fitting.

6. The waterproof structure for a connector according to claim 4 , wherein

any one of the first protrusion part and the second protrusion part has a sectional shape which has a plurality of crest parts in a cross section orthogonal to a circumferential direction thereof, and

the other of the first protrusion part and the second protrusion part is positioned in a valley part between the adjacent crest parts at the time of fitting.

7. The waterproof structure for a connector according to claim 4 , wherein

any one of the first protrusion part and the second protrusion part is formed in a connecting end of the annular member with a main body of the housing, and

the other of the first protrusion part and the second protrusion part presses the surface of the annular member between the connecting end and the protruding end of the annular member.