| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent adherents from adhering and to remove adherents with a simple constitution without interrupting flow detection. SOLUTION: An ultrasonic oscillator 9 formed of electrodes 6 and 8 and a piezoelectric element 7 is provided on the back surface of a thermal-type flow sensor 1 with a heating resistor 2, etc., to detect the quantity of air in an internal combustion engine. The oscillator 9 is excited to propagate bulk elastic waves to the sensor 1, and radiation pressure due to the elastic waves is utilized to prevent adherents from adhering and to remove them. Since any special operation is exerted on the heating resistor 2, there is no need for interrupting flow measurement.</p> |
