Chuck device

A chuck device comprising:

• a cylindrical chuck formed so that at least a part in an axial direction is circumferentially divided, including a first contact part on a first side in the axial direction and a second contact part on a second side opposite to the first side, and configured to hold a bar-like workpiece;
• a tubular outer cylinder covering an outer peripheral side of the chuck, and including, on the first side, a restriction part configured to restrict axial movement of the chuck by abutting on the first contact part;
• and
• a sleeve provided in an axially movable manner on an inner peripheral side of the outer cylinder, and including, on the first side, a pressing part axially driven to abut on the second contact part, wherein
• a movement-restricting tapered face is formed in the restriction part of the outer cylinder,
• a pressing tapered face is formed in the pressing part of the sleeve,
• the chuck includes, in the first contact part, a first tapered face whose outer diameter reduces toward an end on the first side, and includes, in the second contact part, a second tapered face whose outer diameter reduces toward an end on the second side,
• a first angle between the first tapered face and a center axis of the chuck is equivalent to a second angle between the second tapered face and the center axis, or is smaller than the second angle, and
• an angle between the movement-restricting tapered face and the center axis, an angle between the pressing tapered face and the center axis, and an angle between the second tapered face and the center axis are equivalent to each other.