Watertight structure of mounting portion

A watertight structure of a mounting portion comprising:

• a screw hole formed in a fixed member;
• a mounting bolt having a tightening portion formed on one end thereof, having a flange portion formed on the tightening portion, and being screwed into the screw hole;
• a fixing member having a mounting hole formed in part thereof, and being fixed to the screw hole by tightening the mounting bolt with the mounting bolt inserted into the mounting hole having approximately the same diameter as the screw hole;
• a watertight member covering the fixing member, and having an annular projected portion disposed at a position corresponding to the mounting hole so that entrance of a liquid into the mounting hole and the screw hole is prevented, the annular projected portion being larger in a radial direction than the mounting hole and smaller in a radial direction than the flange portion;
• and
• an interposing member, interposed between the flange portion and the fixing member, having a surface of contact thereof with the fixing member that extends in parallel to the fixing member and in the radial direction of the mounting hole, being larger in a radial direction than the mounting hole and smaller in a radial direction than the annular projected portion of the watertight member, and having a height in an axial direction lower than the height of the annular projected portion so that the flange portion properly biases the annular projected portion at the time of tightening the bolt.