Tool clamp device and machine tool

A tool clamp device on which a rotating tool is detachably mounted, the tool clamp device comprising:

• a tool holder that holds the rotating tool, the tool holder including a clamping mechanism part;
• and
• a first piston that reciprocates in an axial direction of a predetermined axis about the predetermined axis, the first piston having substantially a cylindrical tube shape having a hollow inside, the first piston including an inner surface,
• the tool holder being at least partially inserted in the first piston;
• the first piston including clamping mechanism part includes one of a first facing section and a second facing section that face each other in the axial direction of the predetermined axis,
• the first and the second facing sections being configured on the inner surface,
• the clamping mechanism including the locking part protruding in a radial direction of the predetermined axis,
• the locking part being configured between the first and second facing sections at the tool holder,
• the first piston, in a state in which the first piston is configured outside with respect to the tool holder in the radial direction of the predetermined axis, reciprocating between a first position at which the locking part and the first facing section are in contact with each other and the clamping mechanism part is operated in a clamped state of clamping a rotating tool, and a second position at which the locking part and the second facing section are in contact with each other and the clamping mechanism part is operated in an unclamped state of unclamping the rotating tool,
• the tool clamp device further comprising
• a second piston that moves the first piston to a third position located between the first position and the second position in the axial direction of the predetermined axis,
• when the first piston is positioned at the third position, the clamping mechanism part being held in the clamped state, and the locking part being separated from the first facing section and the second facing section.