WORKPIECE MEASURING DEVICE, COLLISION PREVENTING DEVICE, AND MACHINE TOOL

Disclosed are a workpiece measuring device, a collision preventing device, and machine tool, which achieve easy acquisition of three-dimensional data relating to the shape of a workpiece, the data being used for preventing a collision between the workpiece and part of the machine tool. A measuring unit (15) that is mounted to a main shaft to which a tool for working a workpiece to be worked is attached and that scans and measures the distance to the workpiece in a noncontact manner, and a shape recognition unit (23) that generates a three-dimensional mesh structure formed by dividing space into polyhedrons, calculates coordinates of a measuring point of the workpiece on the basis of information relating to the measured distance to the workpiece, and creates a measured shape map on condition that when the ratio of the number of times the calculated measuring point is included in one unit of the three-dimensional mesh structure to the number of times the position of the workpiece corresponding to the one unit is scanned is greater than or equal to a predetermined threshold vale, the one unit is the shape of the workpiece are provided.