| 摘要 |
PURPOSE:To make the early detection of the abnormality of a press possible and to prevent the damage of a driving device by detecting the rate of change in the rotating periods of a rotating member coupled by means of a clutch to the slide of the press and comparing the same with a preset permissible rate of change. CONSTITUTION:Means for detecting the rotating periods of a rotating member 1 of a press consisting of a dog 3, a detecting switch 5, a signal generating circuit 9, a transmitter 7 for reference pulses (b), a counter 11, a latch 13, etc. and a detector 15 for detecting the position of the slide of the press are provided. The rotating period Talpha during idling of the member 1 and the rotating period Tbeta at the timing angle when load is exerted upon the slide are determined, and Tgamma=Talpha-Tbeta is operated in a microcomputer 17. The Tgamma and the permissible change range Tx of the rotating period set by a keyboard switch 19 are compared and when Tgamma>Tx, an abnormal signal is outputted to a display part 21. |
