CLAMP JIG

PROBLEM TO BE SOLVED: To solve a problem in a conventional clamp jig wherein large work burden is applied to a worker because rotation work of a shaft and moving operation of a clamp member are required for the worker when clamping and removing a workpiece. SOLUTION: Rotation torque of the shaft 3 is transmitted to the clamp member 10 through a first friction member 11 and a second friction member 12. Moreover, rotation in one direction (rotation in clamp direction) of the clamp member 10 is stopped at a clamp position by a clamp position locking member 16, and rotation in the other direction (rotation in release direction) of the clamp member 10 is stopped at a clamp release position by a release position locking member 17. Consequently, the clamp member 10 is automatically moved to the clamp position by rotating the shaft 3 in one direction, and the clamp member 10 is automatically moved to the clamp release position only by rotating the shaft 3 in the other direction so that the work for attaching and detaching the workpiece 9 becomes easy.