METHOD AND DEVICE FOR DETECTION OF REVOLUTION OF WORK IN HARDENING DEVICE OF SHAFT OR THE LIKE

摘要

PURPOSE:To detect whether hardening is accomplished with a simple device while the work revolves normally by detecting whether a shaft or the like is hardened or not while revolving normally, from whether a tail center revolves normally or not. CONSTITUTION:A disc 12 formed with plural notches 121 at equal intervals in a pivotally fitted circumferential part, a contactless switch 13 and a discriminating device 14 connected to the switch 13 are provided to the shaft part of a tail center 3. The device 14 detects the successive attaching and detaching of the recesses 122 in the circumferential part of the disc 12 revolving together with the center 3 to and from the switch 13 and compares the pulselike detection signal outputted from the switch 13 and the prescribed number of pulses per preset unit time. It discriminates the revolving direction of the shaft or the like by deciding said state to be normal when the number of the detection signals attains the prescribed number of the pulses and to be not when it does not.