Chuck device

A chuck device comprising:

• a plurality of rods provided with workpiece holding claws for holding a workpiece supplied to a machine tool;
• a support body for supporting each of the plurality of rods;
• a housing for swingably accommodating each of the plurality of rods around the support body;
• and
• a drive body for integrally moving forward and backward the plurality of rods with respect to the housing,
• wherein the housing has a workpiece contact surface that is arranged so as to face the workpiece holding claws,
• wherein, when holding of the workpiece is released, the plurality of rods integrally swings so that the workpiece holding claws are moved away from the workpiece contact surface of the housing and moved away from each other, and
• wherein, when holding the workpiece, after the plurality of rods integrally swings so that the workpiece holding claws are brought close to the workpiece contact surface of the housing and brought close to each other, the plurality of rods moves integrally in parallel with the forward/backward moving direction of the drive body to bring the workpiece holding claws into contact with the workpiece,
• wherein the chuck device further comprises a rod swing mechanism for swinging each of the plurality of rods around the support body,
• wherein the rod swing mechanism has a guide groove and a protrusion for engaging with the guide groove,
• wherein, when the protrusion and the guide groove are engaged with each other, the rod is parallel to the forward/backward moving direction of the drive body, and
• wherein, when the protrusion and the guide groove are not engaged with each other, the rod is tilted with respect to the forward/backward moving direction of the drive body,
• wherein the guide groove of the rod swing mechanism is formed in the rod, and
• wherein the protrusion of the rod swing mechanism is formed in the housing,
• wherein an elastic body, which urges the rod so that each of the workpiece holding claws of the plurality of rods is brought close to each other, is interposed between the rod and the drive body.