Patent attributes
The method for detecting any clamping malfunction of the work within the machine tool which clamps both ends of the work with clamping mechanisms 23, 24 of a pair of headstocks 19, 29, and processes the work by spinning the work through synchronous rotation of main spindles 21, 22 of the pair of headstocks by servomotors 33, 34, wherein, after clamping the both ends of the work 27 with the clamping mechanisms 23, 24 of the respective headstocks 19, 20, and while both the servomotors 33, 34 of the headstocks are in a servo-ON state, a command for a minute angle α rotation is given to the servomotor 34 of only one of the headstocks, and at this point, any malfunction in clamping is determined when a current or torque generated within the servomotor of one or the other of the headstocks is smaller than a predetermined value.