There is provided a machine tool comprising: a moving cover 4 that opens or closes a machining chamber M; a blowout unit including a blowout port 42 that releases gas so as to cover an opening region Op generated when the moving cover 4 is moved from a closed position toward an open position; and a control unit that changes an amount of the gas released from the blowout port 42 according to an opening degree L of the opening region Op.

A spindle device includes a spindle shaft, a spindle housing, and a chuck portion as a rotating member. The chuck portion has, formed therein, a suctioning passage through which air suctioned from the outside flows. The spindle shaft has a first guide passage which guides air flowing through the suctioning passage to a clearance between the inner wall of the spindle housing defining a through hole in which the spindle shaft is inserted and the outer wall of the spindle shaft facing the inner wall, by way of the interior of the spindle shaft. The spindle housing has, formed therein, a second guide passage configured to guide the air guided to the clearance, to the outside.

A machine tool comprising tool spindle (12) having a chuck (26) and a spindle motor, in which the chuck (26) can be actuated for the purpose of receiving and releasing a tool, a sealing air channel (40) is provided which extends at least partially radially outside the chuck (26). The sealing air channel (40) terminates in or at a protective cap (34).

A chuck unit as a rotating member of a spindle device includes a base portion fixed to one end of the spindle shaft, an attaching portion detachably attached to a side of the base portion that is located on an opposite side of the base portion from the one end of the spindle shaft, and an accommodation space arranged on a communication passage so as to accommodate a filter.

A chip antiscatter mechanism is included and configured to suppress scattering of chips generated during machining of a machining object. The chip antiscatter mechanism includes chip stirring means configured to stir the chips, by jetting a gas into a dry machining region above a table including the machining object, fluid curtain forming means configured to form a fluid curtain by jetting a fluid such as liquid or gas membranously from above to an outside of the dry machining region so as to surround the dry machining region, and to form a closed region including the dry machining region by the membranous fluid curtain, and discharging means configured to receive and discharge the fluid jetted membranously by the fluid curtain forming means.

To provide a rotary table device that can prevent the occurrence of malfunction before it happens. A rotary table device equipped with both or one of a clamping mechanism and purge mechanism which operate by way of working fluid, the rotary table device including: a detection unit that detects a pressure or flow rate of the working fluid; a transition information storage unit that acquires and stores transition information related to transition of a pressure value or flow rate value of the working fluid detected by the detection unit; a judgment value storage unit that stores in advance a plurality of sets of judgment value information related to judgment values for judging a pressure value or flow rate value of the working fluid; and a notification unit that notifies of notification information according to the pressure value or flow rate value of the working fluid, based on the transition information stored in the transition information storage unit and the plurality of sets of judgment value information stored in the judgment value storage unit.

A spindle device includes a spindle shaft, a spindle housing, and a chuck portion as a rotating member. The chuck portion has, formed therein, a suctioning passage through which air suctioned from the outside flows. The spindle shaft has a first guide passage which guides air flowing through the suctioning passage to a clearance between the inner wall of the spindle housing defining a through hole in which the spindle shaft is inserted and the outer wall of the spindle shaft facing the inner wall, by way of the interior of the spindle shaft. The spindle housing has, formed therein, a second guide passage configured to guide the air guided to the clearance, to the outside.

A chuck unit as a rotating member of a spindle device includes a base portion fixed to one end of the spindle shaft, an attaching portion detachably attached to a side of the base portion that is located on an opposite side of the base portion from the one end of the spindle shaft, and an accommodation space arranged on a communication passage so as to accommodate a filter.

A chip antiscatter mechanism is included and configured to suppress scattering of chips generated during machining of a machining object. The chip antiscatter mechanism includes chip stirring means configured to stir the chips, by jetting a gas into a dry machining region above a table including the machining object, fluid curtain forming means configured to form a fluid curtain by jetting a fluid such as liquid or gas membranously from above to an outside of the dry machining region so as to surround the dry machining region, and to form a closed region including the dry machining region by the membranous fluid curtain, and discharging means configured to receive and discharge the fluid jetted membranously by the fluid curtain forming means.

A machine tool includes a rotation indexing device and an abnormality determination device. The rotation indexing device including a clamp device configured to maintain a rotary shaft at an indexed angular position and an air purge device configured to supply compressed air to a space within a frame. The abnormality determination device includes a pressure sensor configured to output a pressure signal according to a pressure in a supply pipe conduit of the air purge device, and a determinator configured to determine presence or absence of an abnormality, based on the pressure signal from the pressure sensor.