| 摘要 |
PURPOSE:To stop a drawing machine upon detecting the failure of a die and to decrease the amt. of the defective to be produced by detecting the stress wave generated during drawing by means of a sensor attached to the die or die case. CONSTITUTION:A sensor 4 using a piezoelectric element is attached to a die case 3 or die 2 and the stress wave generated from the friction sur face between the die 2 and a wire 1 is transduced to an electrical signal by the sensor 4 during drawing. The signal is then passed through a preamplifier 5, a filter 6 and a main amplifier 7 and is outputted in the form of the DC voltage proportional to the magnitude of an effective value by an effective value voltmeter 8. Said signal is inputted to a control device 9, and when the input voltage exceeds a set value, the device 9 outputs a stop signal to stop the drawing machine. |
