| 摘要 |
<p>PURPOSE:To move a device rapidly with a simple circuit by obtaining a time at which one of the detecting means which are mutually moving in the opposite directions detects one end part after the other detected the other end part and moving said device by the period of time proportionate to the obtained time. CONSTITUTION:Temp. detectors 28, 30 are moved at an equal speed in the mutually opposite directions from the middle of a fixed part to the end part sides of a cast piece 4 respectively and, when they arrived at the end parts of the cast piece 4, a pulse of H level is generated in their respective output signals R, L based on the temp. difference between the cast piece 4 and a roller table 2. In this case, if a pulse of H level is generated earlier in the output signal R of the detector 28, a flip flop 36 is set causing its output signal XR to become H level. Also, when pulses are generated in the output signals R, L of the detectors 28, 30 respectively, output signals ZR, ZL become H level. Then, an exclusive logic circuit 58 makes its output signal H level during the time from the detection of the end part by the detector 28 to the detection of the end part by the detector 30. A motor 10 is operated for the period of the H level to move a centering device 6 to the detector 30 side.</p> |
