| 摘要 |
PURPOSE:To reduce the number of parts of the titled detector by providing a light emitting element and a light receiving element to structural material of a grill and eliminating the need for a frame, etc., for exclusive use to support said elements. CONSTITUTION:A light emitting diode 2 is fixed by brackets 6 and 7. Furthermore, the harness 4 is installed along a groove of the rear of the front grill 1. On the other hand, a phototransistor 3 and its harness 5 are installed by the same means as the diode 2. Further, slits 8 to prevent the penetration of the dust or the mud are provided to the brackets 6 and 7 of the diode 2 and the transistor 3. Then, when the dust, etc., are passed through between the diode 2 and the transistor 3, the extinction rate is changed and a decision part distinguishes the dust and black smoke from others. At this time, when the decision part decides to be the dust and the black smoke, it sends a signal to a servomotor and actuates an inside and outside air changeover damper so as to intercept the outside air. In this way, the number of parts of the titled detector can be reduced. |
