CONDITION DETERMINATION METHOD OF TEMPERATURE DETECTION POSITION FOR USE IN THERMAL DISPLACEMENT AMOUNT ESTIMATION DEVICE OF MACHINE TOOL

PROBLEM TO BE SOLVED: To provide a condition determination method of a temperature detection position for use in a thermal displacement amount estimation device of a machine tool in which the thermal displacement amount can be estimated with high accuracy while reducing the number of blocks divided.SOLUTION: A condition determination method of a temperature detection position assumes multiple third temperature distributions (θ3to θ3) for providing displacement so as to complement standard difference trends (δ2-δ1) between a first thermal displacement amount (δ1) and a second thermal displacement amount (δ2), and previously calculates multiple third thermal displacement amounts (δ3, δ3, ..., δ3). The third thermal displacement amount (δ3) configured so that the difference trends (δ3-δ2, ..., δ3-δ2) with each of the second thermal displacement amount (δ2) and the multiple third thermal displacement amounts (θ3to θ3) may cancel the standard difference trends (δ2-δ1) is selected. A difference degree (r) capable of cancelling best the standard difference trends (δ2-δ1) is calculated, and the optimum temperature distribution (θg) is calculated, and thereby the temperature detection position corresponding to the optimum temperature distribution (θg) is determined.SELECTED DRAWING: Figure 5 【課題】分割するブロックの数を少なくしつつ、高精度な熱変位量が推定できる、工作機械の熱変位量推定装置に用いる温度検出位置の条件決定方法を提供する。【解決手段】温度検出位置の条件決定方法は、第一熱変位量（δ１）と第二熱変位量（δ２）との基準相違傾向（δ２−δ１）を補完するような変位を与える複数の第三温度分布（θ３1〜θ３j）を想定し、複数の第三熱変位量（δ３1、δ３2、・・・、δ３ｊ）を予め算出する。基準相違傾向（δ２−δ１）を、第二熱変位量（δ２）と複数の第三熱変位量（θ３1〜θ３j）のとのそれぞれとの相違傾向（δ３１−δ２、・・・、δ３ｊ−δ２）が打ち消すような第三熱変位量（δ３f）を選択する。基準相違傾向（δ２−δ１）を最もよく打ち消すことができる相違度合い（ｒ）を算出し、最適温度分布（θｇ）を算出し、当該最適温度分布（θｇ）に対応する温度検出位置を決定する。【選択図】図５