Patent ID: 8485593

Claim:
A drain plug fitted to a drain hole formed in a body panel at an end edge part thereof, the body panel being formed of a pair of outside and inside panels, a space between the pair of panels being widened toward a prescribed direction from the end edge part, the drain plug comprising: a head part arranged on a peripheral edge of the drain hole from a front side, so as to cover the drain hole; and an engaging leg formed on a back surface of the head part, so as to be engaged with the peripheral edge of the drain hole from a back side by being inserted thereinto, wherein the engaging leg includes: a frame wall formed of a front wall and both side walls, so as to be extended in the prescribed direction while being separated from the head part; an opening part provided in a rear part of the frame wall, so as to face the end edge part of the body panel; engaging parts formed on both the side walls, so as to be engaged with the peripheral edge of the drain hole from the back side; and a guide surface formed on the front wall facing the head part, so as to guide the engaging parts to pass through the drain hole, and wherein the head part includes: a thick part having a first thickness; a thin flange part having a second thickness smaller than the first thickness and extending from a peripheral edge of the thick part, so as to elastically abut on the peripheral edge of the drain hole from the front side; and pressing protrusions formed on a back surface of the thick part at positions facing to the engaging parts on the engaging leg, so as to abut on the peripheral edge of the drain hole from the front side.