| 摘要 |
PURPOSE:To early point out breakage of ribbon, secondary swist, mottles of yarn and to prevent the occurrence of abnormality in the next process by comparing the detected tension of a wound yarn with a preset reference value, and generating an alarm signal when the deviation is out of a designated range. CONSTITUTION:The tension of a wound yarn is detected by a counter to be compared with a reference value from a reference value set device 12 by a comparator circuit, and dry found deviation is fed back to PID arithmetic circuit 20, so that the rotating speed of driving motors 1, 1' is suddenly decreased to lower the tension of the yarn below a preset value. As the arithmetic circuit 20 properly operates, however, the rotating speed is again increased up to the peak of a value having the absolute value smaller than that of the peak value at the first time of increasing the speed, so as to heighten the tension of the yarn. Accordingly, the change direction and rate of yarn tension is detected to detect a change pattern by comparison means according to the change direction and rate of tension, so that the occurrence of abnormality, so-called Secondary twist can be recognized and input to an alarm circuit 18. Further it is input to a memory circuit to sort a yarn not to be sent to the next process. Thus, the occurrence of trouble can be prevented. |
