Machine tool and method for measuring a workpiece

A machine tool, comprising:

• a workpiece mount comprising at least one workpiece holder for accommodating a workpiece,
• a tool unit comprising a tool spindle for accommodating and driving a tool wherein the tool unit is movable along a feed axis towards the workpiece, wherein the tool unit further comprises a position transducer being configured for detecting actual positions of the tool unit along the feed axis,
• a measuring device which is accommodated at the tool unit, wherein the measuring device comprises at least two measuring probes, wherein the at least two measuring probes are spaced apart in a measuring configuration by a basic spacing defining a measurement region, wherein the basic spacing is selected to be greater than a known reference dimension, and
• a control device which is connectable to the measuring device and the tool unit, wherein the control device is coupled with the position transducer of the tool unit, and wherein the control device is configured for
• acquiring values detected by the at least two measuring probes
• detecting the actual position of the tool unit along the feed axis, thereby determining the basic spacing, and
• determining an actual spacing on the basis of a displacement path of the tool unit when probing a workpiece with the at least two measuring probes under consideration of the known reference dimension.

A method for measuring a workpiece in a machine tool, said method comprising the following steps:

• providing a measuring device attached to a tool unit, wherein the tool unit is movable in relation to a workpiece along a feed axis, wherein the measuring device comprises at least two measuring probes,
• adjusting a basic spacing between the at least two measuring probes which is selected to be greater than a known reference dimension of a reference geometry, and wherein the basic spacing defines a measurement region,
• accommodating the reference geometry in the machine tool,
• inserting the reference dimension into the measurement region,
• moving the measuring device along with the tool unit in relation to the reference geometry and probing the reference dimension with the measuring probes, thereby detecting actual positions of the measuring device and, as a result, detecting a displacement path of the measuring device, and
• determining the basic spacing under consideration of the reference dimension and of the actual positions of the measuring device when probing.