| 摘要 |
PURPOSE:To detect a defect at the edge of a cutting tool to maintain accurate machining operation of an unmanned machine tool by comparing the change in voltage in closed electric circuit closed when the tool edge is brought in contact with the work to be machined and the change in number of AE counts per unit time of the AE signals. CONSTITUTION:An electric closed circuit is established when the tool edge 2 comes in contact with the work 1 to be machined with the contact point 4 on. The change in current due to contact between the tool edge 2 and the work 1 is detected by a resistance 5, and the current change signal issured therefrom is converted into a change in voltage at a discriminator 14. The acoustic emission signals (AE signals) are detected by a detector 10, and the number of AE counts is converted into the number of change per unit time at the discriminator 14. By plotting these changes with the cutting time on the axis of abcissas, both a voltage drop and the AE signals are seen generated when the tool edge is broken, a rise in voltage and the AE signals when cut chips are stuck around the tool edge, and a voltage drop but no AE signal when cutting oil enteres between the tool edge and the work. Thus, the type of damage of trouble can be known to some extent. |
