Foreign substance blocking device of vehicle seat rail

A foreign substance blocking device for a vehicle seat rail, the foreign substance blocking device comprising:

• a lower rail configured to extend lengthwise along a floor panel of a vehicle, the lower rail configured to be fixedly installed on the floor panel, the lower rail including an open inner area;
• an upper rail coupled to the lower rail and configured to be mounted on a seat cushion, the upper rail configured to enable the seat cushion to be slidably movable along the lower rail, the upper rail being slidably movable toward a foremost position in a tiling walk-in mode;
• and
• a rail cover coupled to the lower rail and disposed to be in contact with an upper surface of the upper rail, the rail cover configured to be rotatably moved in conjunction with sliding movement of the upper rail toward the foremost position in the tiling walk-in mode such that the open inner area of the lower rail is shielded by the rail cover.