| 摘要 |
<p>PURPOSE:To hold a sensor part at a predetermined position at all times and correctly measure an amount of suction air by using a shape memory alloy for a lead wire. CONSTITUTION:When the pressure of a compressed cleaning air hits a heat resistance element, 9, lead wires 14a, 14b buffer a stretching stress. When the compressed air is relatively weak, a stress buffering part is within an area of an elastic deformation. Therefore, the lead wires return to the original state when the air is finished to be blown, and a sensor part alike returns to a predetermined position against the suction air. If the blown compressed air is strong, the stress buffering part is deformed beyond the elastic deformation. However, the stress buffering part is returned to the original shape owing to a shape memory action when an engine is started to flow a current to a platinum wire 16 of the element 9 and the heat generated by the platinum wire is transmitted to the wires 14a, 14b. The stress buffering part is turned to be at right angles to the flow of the air, so that a flow velocity of the suction air is correctly measured.</p> |
