Machine tool and method for changing tools on this machine tool

A machine tool which comprises at least one working spindle with a tool-holding fixture for tool holders carrying tools, and a tool changer with a gripper for the tool holder in order to transfer the tool holder between a magazine position, which is spaced apart from the tool-holding fixture, and a working position in the tool-holding fixture, there being provided in the working spindle a clamping system with a clamping apparatus by means of which a tool holder inserted into the tool-holding fixture is fixed,

• wherein the clamping system additionally comprises a retaining apparatus for positively holding a tool holder situated in the tool-holding fixture, and
• wherein the clamping system comprises a mandrel which, by means of a stroke in the direction of a rotational axis of the at least one spindle, actuates both the clamping apparatus and the retaining apparatus, and
• wherein the clamping apparatus comprises first nipper segments which can be moved between a radially outer position, in which they engage in a hollow shank of the tool holder and fix the latter, and a radially inner position, in which they release the hollow shank,
• wherein the retaining apparatus comprises second nipper segments which can be moved between a radially outer position, in which they engage in the hollow shank of the tool holder and retain the latter in a rotationally fixed manner in the tool-holding structure, and a radially inner position, in which they release the hollow shank, and
• wherein the second nipper segments are configured to be actuated by the mandrel to perform the retaining of the tool holder before the first nipper segments are actuated by the mandrel to perform the fixing of the tool holder.