Chuck
In the case of a clamping device ( 1 ) for holding a workpiece ( 3 ) to be machined by a machine tool ( 2 ), which is used in particular as a clamping chuck, vice or zero point clamping system, consisting of a housing ( 4 ), a supporting element ( 6 ), which is a component of the housing ( 4 ) or is fastened thereto, and thereby forms a supporting surface ( 6 ′), on which the respective workpiece ( 3 ) rests during the machining process, at least one clamping jaw ( 7 ) that is mounted in the housing ( 4 ) so it is axially movable and a counter-stop formed by the housing ( 4 ) or an axially movable clamping jaw ( 8 ), between which the workpiece ( 3 ) is clamped in the region of the supporting surface ( 6 ′) or at least three clamping jaws ( 7, 8, 9 ) mounted in the housing ( 4 ) so they are axially movable, between which the workpiece ( 3 ) is clamped in the region of the supporting surface ( 6 ′), a reliable and verifiable monitoring of the distance between the workpiece ( 3 ) and the supporting surface ( 6 ′) and/or the clamping jaws ( 7, 8, 9 ) is supposed to take place at the clamping device ( 1 ) before and during the entire machining process, without extensive constructional measures being required for this. This is achieved in that at least one free space ( 11 ) is integrated in the housing ( 4 ), the axis of symmetry of which runs perpendicular to the supporting surface ( 6 ′) and which faces the clamped workpiece ( 3 ) with the open front side, and/or that at least one free space ( 11 ) is integrated in one of the clamping jaws ( 7, 8, 9 ), which free space leads to the respective clamping surface ( 7′, 8′, 9 ′) of the clamping jaws ( 7, 8, 9 ), that a proximity sensor ( 12 ) is inserted in the respective free space ( 11 ), that, via the proximity sensor ( 12 ), a monitoring area ( 13 ) is formed between the supporting surface ( 6 ′) and the workpiece ( 3 ), which is monitored by an analysis unit ( 14 ) with respect to the presence of the workpiece ( 3 ).
1 . A clamping device ( 1 ) for holding a workpiece ( 3 ) to be machined by a machine tool ( 2 ), the clamping device comprising:
a housing ( 4 ),
a supporting element ( 6 ), which is a component of the housing ( 4 ) or is fastened thereto, and thereby forms a supporting surface ( 6 ′), on which the respective workpiece ( 3 ) rests during the machining process,
at least one clamping jaw ( 7 ) that is mounted in the housing ( 4 ) so it is axially movable and a counter-stop formed by the housing ( 4 ) or an axially movable clamping jaw ( 8 ), between which the workpiece ( 3 ) is clamped in the region of the supporting surface ( 6 ′) or at least three clamping jaws ( 7 , 8 , 9 ) mounted in the housing ( 4 ) so they are axially movable, between which the workpiece ( 3 ) is clamped in the region of the supporting surface ( 6 ′),
wherein
at least one free space ( 11 ) is integrated in the housing ( 4 ), the axis of symmetry of which runs perpendicular to the supporting surface ( 6 ′) and which faces the clamped workpiece ( 3 ) with the open front side, and/or that at least one free space ( 11 ) is integrated in one of the clamping jaws ( 7 , 8 , 9 ), which free space leads to the clamping surface ( 7 ′, 8 ′, 9 ′) associated with each of the clamping jaws ( 7 , 8 , 9 ),
a proximity sensor ( 12 ) is inserted in the respective free space ( 11 ),
and via the proximity sensor ( 12 ), a monitoring area ( 13 ) is formed between the supporting surface ( 6 ′) and the workpiece ( 3 ), which is monitored by an analysis unit ( 14 ) with respect to the presence of the workpiece ( 3 ),
characterized in that
the distance of the free spaces ( 11 ) to a center point ( 21 ) of the housing ( 4 ) can be adjusted variably as a function of the diameter of the workpiece ( 3 ) to be machined.
2 . The clamping device according to claim 1 , characterized in that three free spaces ( 11 ) are arranged in the supporting surface ( 6 ′) in a 120° separation angle to one another.
3 . The clamping device according to claim 1 , characterized in that the free spaces ( 11 ) in the supporting surface ( 6 ′) are arranged in a circular path ( 20 ), which runs around the center point ( 21 ) of the housing ( 4 ).
4 . The clamping device according claim 1 , characterized in that one of the clamping jaws ( 7 , 8 or 9 ) is arranged between two adjacent free spaces ( 11 ) in the supporting surface ( 6 ′).
5 . The clamping device according to claim 1 , characterized in that the energy needed for the operation and/or the electrical signals required for the communication between the respective proximity sensor ( 12 ) and the analysis unit ( 14 ) are transmitted by means of an inductively operated interface ( 16 ), which is arranged in the housing ( 4 ) or outside of the housing ( 4 ).
6 . The clamping device according to claim 1 , characterized in that each of the proximity sensors ( 12 ) inserted in the free space ( 11 ) is attached to the analysis unit ( 14 ) by means of an electrical line ( 15 ) or an inductive interface ( 16 ).
7 . The clamping device according to claim 6 , characterized in that the analysis unit ( 14 ) is arranged on an axis of symmetry ( 21 ′) of the housing ( 4 ) and that the electric lines ( 15 ) of the respective proximity sensors ( 21 ) are bundled at the analysis unit ( 14 ) and are guided outwardly therefrom in a bundled manner.
8 . The clamping device according to claim 1 , characterized in that that each of the proximity sensors ( 12 ) forms the monitoring area ( 13 ) of 0.02 mm to 3 mm and that the monitoring area ( 13 ) is designed as a field projecting perpendicularly from the supporting surface ( 6 ′), into which field the workpiece ( 3 ) to be clamped dips.
9 . The clamping device according to claim 1 , characterized in that the respective proximity sensor ( 12 ) is operated inductively, capacitively or light waves are emitted respectively to determine the distance.