| 摘要 |
<p>PURPOSE:To prevent the deterioration of the accuracy of a detection value by forming as one body a front grille and a horn antenna of a Doppler sensor and providing an opening part of the horn antenna in front of the front grille. CONSTITUTION:An opening part 3a is pierced in a suitable position in front of a front grille 8 of a work use vehicle 7, and the front grille 8 and a horn antenna 3 are formed as one body so that said part becomes a horn antenna opening part of a Doppler sensor 14. This antenna 3 is tapered toward the rear, and to its rear end part, a Doppler sensor module 4 is fixed. In this state, a microwave which has been transmitted from this module 4 is allowed to have directivity by the antenna 3 and radiated from the opening part of the antenna 3. In this case, the horn antenna opening part is provided in front of the front grille 8, and positioned in sufficient height. Accordingly, since a waterproof and dustproof cover is not installed in the horn antenna opening part, there is no loss of a microwave and the Doppler sensor 14 can work with high performance.</p> |
