PURPOSE: To prevent the poor processing of a machine tool by providing on a pallet an actuator for detecting the abnormal drop of hydraulic pressure and also providing on a table a detection part for detecting said abnormality, upon clamping a work to the work plallet with the hydraulic pressure.
CONSTITUTION: In order to fix a work W on a work pallet, the pressurized hydraulic oil supply port 22 of a hydraulic pressure supply device is connected to the pressurized hydraulic oil supply and exhaust port of a work pallet, and pressurized hydraulic oil is forcedly inserted into a hydraulic work clamp via a shutoff valve V to fix the work. And thereafter, the shutoff valve V is closed, and a pressurized hydraulic oil supply port is removed from the pressurized hydraulic oil supply and exhaust port 22 while keeping a state of the pressurized hydraulic oil maintained in the work clamp. When the hydraulic pressure becomes less than the set pressure of the work clamp during the cutting of the work W, i.e., when the hydraulic pressure within the oil passage 19 of a hydraulic cylinder drops, a detection actuator 43 is shifted by a pressure setting spring, and the reduction of the pressure is detected by a detection part 45 on a table, allowing a machine tool to be stopped.
YONEZAWA KEITAROU
KITAURA ICHIROU
YAMADA SOUHEI
