| 摘要 |
<p>In order to prevent wire breakage with a simple configuration, this wire electrical discharge machining device has a configuration that is provided with: a tension control motor (4A) for controlling the tension and feed rate of a wire stretched between a tension control roller and a winding roller by controlling the tension control roller; an external force estimator for calculating an estimate for the external force applied on the tension control motor (4A) as an estimated external force value; an external force determining instrument for determining, on the basis of the estimated external force value, whether or not there is a threat of wire breakage; a machining power source control device for controlling the machining power source so as to reduce the electrical discharge machining energy to be applied between the wire and the workpiece when it is determined that there is a threat of wire breakage; a motor position detector for detecting the rotation position of the tension control motor (4A); and a motor control device (6A) for controlling the tension control motor (4A) on the basis of the rotation position of the tension control motor (4A) so that the wire feed rate is kept within a specified range.</p> |
