| 摘要 |
PURPOSE:To determine whether an operation of a valve mechanism is good or bad, by catching an operation sound (impact vibration) of the mechanism by an AE sensor. CONSTITUTION:A valve is opened and closed by making a drive signal flow from a driving part 19 to a driving coil of a valve mechanism 1 fitted to a throttle body 3. An operation sound at the time when the valve is opened and closed is sensed by an AE sensor 11 and amplified and detected and a signal thus obtained is determined by a microcomputer 18. The signal is sampled only during a period T2 being shorter than a period T1 of making a current flow through an exciting coil 49, and an operation is determined as good when the average value of the sampled signals is a prescribed value or above. |
