DETERMINATION METHOD AND DETERMINATION PROGRAM

To realize a determination method for determining whether or not a shaft has been correctly press-fitted in a shaft hole in a rotor core through a nondestructive test.SOLUTION: A determination method according to one aspect of the present disclosure includes steps of detecting a press-fitting stroke amount and a press-fitting load of a shaft into a shaft hole in a rotor core, obtaining the inclination of the relation between the press-fitting stroke amount and the press-fitting load in a first press-fitting stroke section, obtaining an approximation straight line of the relation between the press-fitting stroke amount and the press-fitting load in a second press-fitting stroke section, estimating a flow start load of starting a plastic flow of the material of the shaft inside the rotor core on the basis of the approximation straight line and the relation between the press-fitting stroke amount and the press-fitting load, and determining that the shaft has been press-fitted into the shaft hole in the rotor core when the inclination in the first press-fitting stroke section is equal to or less than a first threshold and the flow start load is equal to or less than a second threshold.SELECTED DRAWING: Figure 2 【課題】非破壊検査によってシャフトがロータコアのシャフト孔に正常に圧入されたか否かを判定することが可能な判定方法を実現する。【解決手段】本開示の一形態に係る判定方法は、シャフトにおけるロータコアのシャフト孔への圧入ストローク量及び圧入荷重を検出する工程と、第１の圧入ストローク区間での圧入ストローク量と圧入荷重との関係の傾きを導き出す工程と、第２の圧入ストローク区間での圧入ストローク量と圧入荷重との関係の近似直線を導き出す工程と、近似直線と、圧入ストローク量と圧入荷重との関係と、に基づいて、シャフトの材料がロータコアの内部で塑性流動を開始する流動開始荷重を推定する工程と、第１の圧入ストローク区間の傾きが第１の閾値以下であって、且つ、流動開始荷重が第２の閾値以下の場合、シャフトがロータコアのシャフト孔に正常に圧入されたと判定する工程と、を備える。【選択図】図２