SPINDLE DEVICE OF MACHINE TOOL

摘要

A spindle device and a tool holder of a machine tool stably ejecting spray coolant from the tip of a tool (19) in a tool holder (18) and suppressing a waste of the spray coolant, wherein the tool holder (18) is fixed to the tip part of a spindle (2) mechanically detachably through clamp means (KR), an extension passage (104) is formed in the state that an in-holder spray coola nt passage (103) formed in the center part of the tool holder (18) is extended rearward, and the in-spindle spray coolant passage (102) formed in the cente r part of the spindle (2) is formed to communicate with the in-holder spray coolant passage (103) through the extension passage (104).