PURPOSE: To provide a device capable of taking in air from the front of a car body and accelerating it so as to jet in front of tires, thereby blowing off water to prevent slip of a car in case of rainy weather.

CONSTITUTION: Air or rain water is taken in from an air inlet 1 on the front of a car body, and is accelerated through a tube 2, the middle part of which is narrowed. The air flow changes its direction to the underside of the car body by the spherical wall 3 to jet from wedge-shaped slits 4 ahead of each tire 6. Thus, the air flow pushes away water screens entering into the underside of the tires.