摘要 |
<P>PROBLEM TO BE SOLVED: To provide a numerical control device and machining method, capable of highly precisely machining a workpiece in a machine tool, and capable of greatly shortening a machining time. <P>SOLUTION: Data showing a relationship between a rotation speed S and a thermal displacement T of a spindle 7 is measured in advance and is stored. With the data, the thermal displacement Tn of the spindle 7 and a standard thermal displacement TO at a contact point Pn of a tool 73 and a workpiece W are found, and a machining error TnO at the contact point Pn is found (Steps 1 to 4). Then, Rotation speeds Sn and SSn of the spindle 7 are decided so that the machining error TnO is within the allowable error An of the workpiece, and the rotation standard speed SO of the spindle 7 commanded in an NC program and the feed standard speed FO of a table 3 are changed (Steps S5 to 9). Because the above treatment is done for each machining portion in a machining step (one machining step) with the same tool 73, the machining time is greatly shorened compared with the past, while the high machining precision for the workpiece is maintained. <P>COPYRIGHT: (C)2013,JPO&INPIT |