| 摘要 |
<p>In the present invention, an eddy current sensor (1) is disposed in a position such that an electromagnetic field that is generated reaches a melt that is filled into a cavity (11). After pouring the melt into the cavity (11) is started, a voltage signal output by the eddy current sensor (1) changes to increase and an output signal of a differentiating circuit (28) within a detection device (21) exceeds a threshold value (Vx) (first step), and if the output signal of the differentiating circuit (28) exceeds a threshold value (Vy) (< Vx) (second step), a controller (27) stores the sensor output value at the time as a reference voltage value (V3) (= Voffset + Vα). Furthermore, if it is detected that the sensor detection value increases by a determination value (ΔVb) from the reference voltage value (V3), solidification of the melt is determined to be completed (third step).</p> |
