| 摘要 |
PURPOSE:To detect whether powder is filled in a pipe or not in the steps of inspecting a final product and on the way of production process according to whether an amplitude of an acoustic wave exceeds a set value or not within a predetermined time interval after a strike is applied by picking up the acoustic wave generated upon application of the strike to the pipe after filling. CONSTITUTION:Dies 24 are processed to be area-reduced by pulling a pipe 21 in a direction of the arrow. A straightening unit 22 applies a suitable tension to a part where a strike sound of other wire of a straightening function should be generated. A strike sound generator 25 is indicated in a side view. An output of a microphone 26 is input to a comparator 29 via an amplifier 27 and a high pass filter 28, which comparator 29 detects whether the amplitude exceeds a set value or not, displays it on a display unit 30, and generates an alarm sound at the time of unfilling. A wire is fed at a speed of 30m/min, a hammer is made to hit three times for two seconds, i.e., an unfilled position is decided at each 33cm of an interval of striking points. Whether the amplitude of a pulsating wave exceeds a set value or not is detected by the comparator 29 until 2msec immediately after the strike sound, and a filled position is effectively detected from its result. |
