| 摘要 |
PURPOSE:To prevent damage due to contact of an electrode with a work in such a way that when incipient tremor is detected during machining, a spindle is controlled so that the electrode can be separated from the work, and it is locked not to be dropped. CONSTITUTION:After sensing signal 19 has been given from a P wave sensor 18 which senses incipient tremor of the earthquake to a servo control circuit 14, when this signal 19 is given as input, a spindle 4 is sent up with it as servo control signal 21 to be given to a servo valve 20. In other words, an electrode 10 is separated from a work 11 until S wave is sensed, and after it has been sent up for the determined rate, the spindle is locked not to be dropped, so that damage due to contact of the electrode 10 with a work 11 at the time of seism can be prevented. |
