HYDRAULIC CHUCK FOR A WINDING MACHINE

A hydraulic chuck for a winding machine is provided to simply reduce pressure of a hydraulic chamber by loosening a knob connected to the hydraulic chamber after winding work, to radially move jaws through a spring, and to easily separate a core from the jaws. A hydraulic chuck(1) for a winding machine includes a case(5), a core fixing unit(30), a pressing unit(40), and a returning unit(50). The case is reversibly rotated by being connected to a rotary shaft(100a) of a driving motor(100). The core fixing unit has a plurality of jaws(20) which are radially moved outside the case by a push rod(15). The pressing unit has a plurality of push bars(42) and a tilting bar(46). The push bars are moved to the inside of the case by being pushed by an end of a core(10). The tilting bar increases pressure of a rear hydraulic chamber(32) of the push rod by movement of the push bar so as to push the push rod forward. The returning unit has a knob(60) to discharge the pressure of the hydraulic chamber and an elastic unit(52) wound around the jaws so as to radially move the jaws inside the case when the pressure of the hydraulic chamber is reduced.