| 摘要 |
PURPOSE:To enable reutilization of a die by stopping a drawing machine before failure of the die and to reduce the cost of the die 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 surface between the die 2 and a wire 1 during drawing is transduced to an electrical signal by the sensor 4. 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. The signal is then inputted to an alarm device 9, and when the input voltage exceeds a set value, the device 9 alarms the failure to an operator by means of a lamp or buzzer, etc. |
