Tool replacement method and nut driver for machine tools

摘要

A spindle (5) has a chuck (9) provided on a distal end (5a) thereof for chucking a tool (11), and a nut (13) screwed to the distal end (5a) and rotatable for tightening and loosening the chucking. The spindle (5) is positioned relative to a nut loosening station provided with a nut loosening driver (43) for driving the nut (13) to rotate in a loosening direction, the nut (13) is loosened by the nut loosening driver (43) to remove from the chuck (9) a first tool (11) to be replaced with a second tool (11), the spindle (5) is positioned relative to a nut tightening station provided with a nut tightening driver (41) for driving the nut (13) to rotate in a tightening direction, and the nut (13) is driven by the nut tightening driver (41) to tight-chuck the second tool (11).