Operating method of a numerical-control machine tool and detection device for implementing such method

An operating method of a numerical-control machine tool that comprises:

• a tool-carrying head (2) which is provided with a tool-holder spindle (3) capable of accommodating tools for machining a piece;
• a movable supporting structure (4) that supports said tool-carrying head (2), and is provided with moving members (12, 15, 18) that are adapted to move the tool-carrying head (2) in a space surrounding the piece to be machined, during machining of the piece;
• and an electronic control device (5) that controls one or more moving members (12, 15, 18) of the movable supporting structure (4),
• said operating method including, before machining of the piece, a calibrating procedure comprising the steps of:
• fitting a detection device (100) into the tool-holder spindle (3) of the tool-carrying head (2), the detection device (100) being adapted to measure values of tilting of the detection device (100) relative to a predetermined reference inertial plane;
• moving the tool-carrying head (2) in space so as to place said detection device (100) in succession in a multitude of control points spread on a first detection plane (P1) and to generate signals based on measurements taken in the multitude of control points, and
• processing the signals arriving from the detection device (100) to create at least a first digital map (M1) that contains the tilting values of the detection device (100) relative to the reference inertial plane, in each of said control points;
• and
• said operating method additionally comprising the step, during machining of the piece, of continuously correcting at least one of the spatial position and the orientation of a machining tool based on said first digital map (M1) that differ from ideal design values due to deformations associated with the movable supporting structure (4).