| 摘要 |
PURPOSE:To improve safety and reliability of work through rapid, secure detection of breakage of a tool by comparing a reference voltage determined by an unloaded voltage with a loaded voltage of a drive device and discriminating when the loaded voltage is lower than the reference voltage to be the tool breakage. CONSTITUTION:When machining a workpiece 7 with a tool 1, voltage of a spindle motor 2 is outputted from a loaded voltage output terminal 3 and sent continuously to a main device 5. On the other hand, a value of loaded memory value multiplied by a dial setting value is set as a reference value for discriminating tool breakage and is inputted in advance in a comparison circuit 6 of the main device 5. Then, a voltage sent from the loaded voltage output terminal 3 is compared with the reference voltage with the comparison circuit 6. If the result is that the loaded voltage is lower, the tool 1 is discriminated to be broken and the lower voltage is outputted as a breakage signal to an NC controller 8 to take specified measures such as to stop machine feed and to light breakage pilot lamp. Accordingly, safety and reliability of work can be improved through rapid, secure detection. |
