| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of correcting thermal displacement for a numerically controlled machine tool suitably used when smooth curved face working is required in a die and the like. SOLUTION: A target position given by a calculation unit 10 for a target position Zpsn in the Z-axis direction calculated for each period of sampling in a numerical control device NC is added with a thermal displacement correction amount Cn calculated by an adding unit AD, is given to a servo control unit 12, and drives a Z-axis driving motor 16 through a servo amplifier 14. A temperature detection unit 24 performing A/D conversion of an analog signal from temperature sensors S1, S2 and converting to a digital amount Tn is provided. Also, a calculation unit 22 for a target value P of the thermal displacement correction amount in the Z-axis direction is provided, and the target value P is given to a thermal displacement correction filtering unit 20. Its output Cn is Cn=P+(Cn-1-P)*EXP(-t/T). COPYRIGHT: (C)2010,JPO&INPIT
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