| 摘要 |
PURPOSE:To prevent the lowering of quantity of light received due to a foreign matter, by arranging an introduction port section of an introduction body facing the front of a vehicle while the introduction port is bent being inclined forward from the rear thereof to separate a dust fluid from the foreign matter. CONSTITUTION:A dust sensor S is made up of a cylindrical introduction body 20, a pair of cylindrical housings 30 and 40, a light emitter 50 and a light receiver 60. An introduction port section 21 of the introduction body 20 is set along the length of a vehicle facing the bumper thereof while the introduction port section 21 is bent by being inclined forward from the rear thereof and dimensions at parts of the introduction body 20 are set at specified values. Then, when a foreign matter such as mud enters into the introduction body 20 on a current together with a dust fluid, it moves straight separating from the current turning upward at the introduction port section 21 as the mass thereof is larger than that of the dust and down hitting the lower part of the inner wall of the introduction port section 21 to be blocked from the base section 22 of the introduction body 20. Thus, only the density of dust of the dust fluid can be measured accurately. |
