WORKPIECE CLAMPING DEVICE IN PLATE STOCK WORKING MACHINE

PROBLEM TO BE SOLVED: To provide a workpiece cramping device in a plate stock working machine which is provided with a sensor to precisely detect if there is a workpiece or not regardless of the wall thickness and positively clamps a thin plate whose end section tends to hang easily at the same time. SOLUTION: A workpiece clamping device in the plate stock working machine characterized in that a clamp base 42 is provided in the workpiece positioning device in the plate stock working machine, an elevating cylinder 133 to elevate a clamp body 103 on the clamp base, a bottom clamp nail 101 is provided in the clamp body and further, a rocking clamp lever 107 is provided on the rocking shaft 109 as the supporting point, and an upper clamp nail 128 which holds the workpiece W in cooperation with the lower clamp nail is provided detachably in the clamp lever, and a clamp cylinder 116 to rock the clamp lever to the clamp body is provided moreover, a workpiece detecting sensor to rock with the clamp lever in the rocking shaft is provided.