| 摘要 |
PURPOSE:To prevent water from penetrating into a motor case as well as to aim at a spot short of a breather hole, by installing a visor part covering the breather hole in a manual operating knob as one body, and also installing a breather passage where an outside air outlet is deflected rearward on the circumference of the visor part in relation to a rotating direction of the knob. CONSTITUTION:A breather passage 24 of a visor part 21 at the lower end part of a manual operating knob 20 is interconnected to the inside of a case 7 through the outside air via each of breather holes 11a and 11b of the motor case 7, making the run of air inside the case 7 attainable therein or therefrom. Simultaneously with this, in order to cope with the water penetrated from the outside, the degree that water collides with guide walls 25a and 25b is made to be larger whereby a direct hit of the water to the inside of the visor part 21 is prevented from occurring. In addition, in the breather passage 24, an outside air outlet 27 is deflected rearward against the rotating direction of the visor part 21 so that water clinging to these guide walls 25a and 25b is blown away from the breather passage 24 of the visor part 21 rotating together with the motor 4 outward by dint of its centrifugal force. And, since these guide walls 25a and 25b are tilted backward to the rotating direction, the water is blown off rearward along this inclined plane, while muddy water penetrating into the backside of these guide walls is drained along the backside by the centrifugal force. |
