| 摘要 |
PURPOSE:To automatically detect the damage of a tool, by dividing the high-frequency and low-frequency components of acoustic emission signal emanating from the tool or a machine tool from each other with a boundary of prescribed frequency and comparing the levels of the high-frequency and low-frequency components with each other. CONSTITUTION:A detector 1 is attached to a tool or a machine tool. An acoustic emission signal is detected by an acoustic emission signal measuring unit. The signal is applied to a frequency discriminator 3 through an amplifier 2 so that the signal is divided into high-frequency components H of 200kHz or more and low-frequency components L ranging from 50 to 200kHz. The ratio H/L of the output levels of both the components is calculated by a divider 4. When the ratio H/L exceeds a reference value, a comparator 5 drives an alarm 6. When the frequency components of 50kHz and more are divided into high-frequency and low-frequency ones with a boundary of 150-300kHz, there is a correlation between the output level ratio H/L and the damage percentage of the tool. According to this fact, the damage of the tool can be detected with a required accuracy. |
