COUPLING DEVICE HAVING COUPLING TOOL, LOOSENING DETECTION DEVICE OF COUPLING TOOL, AND BATTERY MODULE HAVING COUPLING DEVICE

摘要

PROBLEM TO BE SOLVED: To suppress a detection error of loosening of coupling between a male screw member and a female screw member, and detect loosening at shorter time.SOLUTION: The coupling device comprises: a male screw member 22 and a female screw member 25 which are coupled each other; a displacement detection tool 31 in which output voltage to input voltage is changed according to relative rotation displacement of the male screw member 22 to the female screw member 25; and a loosening detection tool 51 for outputting a signal for indicating a loosening state of coupling between the male screw member 22 and the female screw member 25 according to change of the output voltage to the input voltage in the displacement detection tool 31.