| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a machine tool and a motor control method capable of preventing passage of current higher than required for motor to drive a cam mechanism, and preventing a temperature rise of the motor. <P>SOLUTION: In a case of high load operation for vertically moving a tool change arm 30 in tool change operation, a control device 60 of a machining center switches a relay 93 to select a path without a resistor R, and passes high current to a tool change motor 27. Further, in a case of a low load operation for turning the tool change arm 30, the control device 60 switches the relay 93 to select a path having a resistor R, and reduces current to the tool change motor 27. Further, the control device 60 previously stores switching timing between the high load operation and the low load operation as a switching timing table, clocks elapsed time from the start of tool change operation by a timer, and if the elapsed time reaches the switching timing, performs switching of the relay 93. <P>COPYRIGHT: (C)2013,JPO&INPIT |
