METHOD FOR A HEATING OF A TOOL HOLDER BY MEANS OF AN INDUCTION HEATING DEVICE, AND SHRINK-CLAMPING AND/OR UNSHRINK-UNCLAMPING STATION FOR TOOLS

Abstract

A method for a heating of a tool holder by means of an induction heating device for the purpose of a shrink-clamping and/or unshrink-unclamping of tools into and/or from tool holders includes an induction heating unit having at least one, preferably exclusively one, induction coil and is configured to expand by heating at least a portion of the tool holder, in particular at least a clamping region of the tool holder, in a shrink-clamping process or in an unshrink-unclamping process, and the induction coil is moved during an induction heating process.

Claims

1. A method for a heating of a tool holder by means of an induction heating device for the purpose of a shrink-clamping and/or unshrink-unclamping of tools into and/or from tool holders, wherein an induction heating unit comprises at least one, preferably exclusively one, induction coil and is configured to expand by heating at least a portion of the tool holder, in particular at least a clamping region of the tool holder, in a shrink-clamping process or in an unshrink-unclamping process, wherein at least the induction coil is moved during an induction heating process.

2. The method according to claim 1, wherein the induction coil is moved oscillatingly during the induction heating process.

3. The method according to claim 1, wherein during the induction heating process, the induction coil is moved along an axial direction of the tool holder that is to be heated.

4. The method according to claim 1, wherein during the induction heating process, the induction coil and/or the tool holder are/is rotationally moved at least partially around a rotation axis that extends in parallel to an axial direction of the tool holder.

5. The method according to claim 1, wherein a movement range of the induction coil, in which the induction coil is moved during the induction heating process, completely covers a region of the tool holder, in particular the clamping region of the tool holder, which is to be heated in the shrink-clamping process or in the unshrink-unclamping process.

6. The method according to claim 1, wherein a movement range of the induction coil is adjusted depending on the respective tool holder that is to be heated.

7. The method according to claim 1, wherein the induction coil is moved in an axial direction within a maximum movement range of at least 5 mm, preferably at least 10 mm, advantageously at least 20 mm, especially advantageously at least 40 mm, preferentially at least 60 mm, and particularly preferably no more than 100 mm.

8. The method according to claim 2, wherein the induction coil is moved in an oscillating manner with a frequency of at least 0.5 Hz, preferably at least 1 Hz, advantageously at least 2 Hz, especially advantageously at least 5 Hz, preferentially at least 10 Hz, and particularly preferably no more than 20 Hz.

9. The method according to claim 2, wherein following a heating of the tool holder, the oscillating movement of the induction coil is used to apply cooling air onto the heated clamping region of the tool holder.

10. A shrink-clamping and/or unshrink-unclamping station for tools, with an induction heating device for a shrink-clamping and/or unshrink-unclamping of tools into and/or from tool holders, which comprises an induction coil and which is configured at least for carrying out a method according to claim 1.

11. The shrink-clamping and/or unshrink-unclamping station according to claim 10, further comprising a tower unit, which the induction heating device is coupled with and which comprises a drive unit that is at least configured for moving at least the induction heating unit of the induction heating device along the tower unit, the drive unit being configured at least for generating an oscillating movement of the induction heating device, in particular an oscillating movement of the induction heating device relative to the tower unit.

12. The shrink-clamping and/or unshrink-unclamping station according to claim 10, wherein the induction heating device comprises at least one induction coil drive unit, which is configured to oscillatingly move the induction coil relative to the induction heating device in particular relative to a housing of the induction heating device.

13. The shrink-clamping and/or unshrink-unclamping station according to claim 10, further comprising a cooling unit, which has at least one nozzle that is configured to blow cooling air towards a tool holder, the cooling unit being fixedly coupled with the induction heating device that is oscillatable along the axial direction.

Description

DRAWINGS

[0022] Further advantages will become apparent from the following description of the drawings. The drawings show an exemplary embodiment of the invention. The drawings, the description and the claims contain a plurality of features in combination. Someone skilled in the art will purposefully also consider the features individually and will find further expedient combinations.

[0023] It is shown in:

[0024] FIG. 1 a schematic sectional view of a shrink-clamping and/or unshrink-unclamping station with an induction heating device, and

[0025] FIG. 2 a flow chart of a method for heating a tool holder by means of the induction heating device.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0026] FIG. 1 shows a shrink-clamping and/or unshrink-unclamping station 18. The shrink-clamping and/or unshrink-unclamping station 18 is configured for an automated shrink-clamping and/or unshrink-unclamping of tools 12 into and/or from tool holders 14. The shrink-clamping and/or unshrink-unclamping station 18 is configured to carry out a shrink-clamping process on tools 12 for the purpose of a fixation of the tools 12 in tool holders 14 and/or to carry out an unshrink-unclamping process on tools 12 for the purpose of a removal of the tools 12 from tool holders 14. The shrink-clamping and/or unshrink-unclamping station 18 comprises an induction heating device 10. The induction heating device 10 is configured for a heating of the tool holders 14. The tool holders 14 are embodied as shrink-clamp chucks. The tool holders 14 comprise tool receiving openings 40. The tools 12 are implemented as shaft tools. The tools 12 respectively comprise a tool shaft 76. The tools 12 have a work region 78. The tool receiving openings 40 of the tool holders 14 are configured for receiving the tool shaft 76 of a tool 12. Preferentially the tool shaft 76 is, in a state when clamped in the tool holder 14, inserted in the tool receiving opening 40 of the tool holder 14 almost completely, in particular apart from a region measuring maximally 5 mm, preferably maximally 3 mm and preferentially maximally 2 mm. This region is equivalent to an ideal and/or designated insertion and/or clamping depth of the tools 12 in the tool holder 14.

[0027] The induction heating device 10 comprises an induction heating unit 16. The induction heating unit 16 is configured, in the shrink-clamping process and/or in the unshrink-unclamping process, to expand the tool receiving opening 40 of the tool holder 14 by heating. The induction heating unit 16 comprises precisely one induction coil 20. The induction coil 20 is implemented to be movable during an induction heating process. The induction coil 20 is implemented to be oscillatable during an induction heating process. The induction heating unit 16 is configured to generate an induction magnetic field. The induction magnetic field is configured to interact with the material of the tool holder 14 for the purpose of heating and thus for an expansion of the tool holder 14. The induction coil 20 comprises an opening 74. The opening 74 of the induction coil 20 is aligned in parallel to an axial direction 24 of the shrink-clamping and/or unshrink-unclamping station 18 and/or in parallel to an axial direction 24 of the induction coil 20. The induction coil 20 comprises coil windings which are wound around the opening 74 of the induction coil 20. The shrink-clamping and/or unshrink-unclamping station 18 comprises a control and/or regulation unit 80. The control and/or regulation unit 80 is configured at least for applying the induction coil 20 with an alternating current for a generation of an induction magnetic field. An extension of the induction coil 20 in the axial direction 24 corresponds to a minimum region which an induction magnetic field is applied to by the induction coil 20 during the shrink-clamping process or during the unshrink-unclamping process. The induction heating unit 16 comprises a cooling unit 86. The cooling unit 86 is arranged underneath the induction coil 20. The cooling unit 86 is configured for cooling the tool holder 14 subsequently to an insertion of a tool 12 in the tool holder 14 and/or subsequently to a removal of the tool 12 from the tool holder 14.

[0028] The cooling unit 86 comprises a nozzle 38. The nozzle 38 is configured to blow cooling air, in particular pressurized air, in a direction that is perpendicular to the axial direction 24 of the induction coil 20. The nozzle 38 is configured to blow cooling air towards a tool holder 14. The nozzle 38 is configured to blow cooling air onto a tool holder 14 previously heated by the induction coil 20. The cooling unit 86 is fixedly coupled with the induction heating device 10 that is capable of being oscillated along the axial direction 24. The cooling unit 86 is arranged underneath the induction coil 20. The cooling unit 86 forms a cooling ring 32. The cooling ring 32 comprises a plurality of nozzles 38, which are oriented toward an interior of the cooling ring 32. The induction coil 20 and the cooling ring 32 are centered around a shared axis 30, which extends along a center of the opening 74 of the induction coil 20.

[0029] The shrink-clamping and/or unshrink-unclamping station 18 comprises a tower unit 84. The induction heating device 10 is coupled with the tower unit 84. The tower unit 84, in particular a main extension direction 90 of the tower unit 84, extends in parallel to the axial direction 24 of the induction coil 20. The induction heating unit 16 is movably supported on the tower unit 84. The induction heating unit 16 comprises a carriage 96. The carriage 96 of the induction heating unit 16 is configured to movably support the induction unit 16 on the tower unit 84. Preferentially the induction heating unit 16 comprises at least two carriages 96, as a result of which a particularly high precision of the movement of the induction heating unit 16 is achievable. It is possible for the induction heating unit 16 to be moved up and down on the tower unit 84, along the main extension direction 90 of the tower unit 84. The induction heating unit 16 can be moved up and down on the tower unit 84 in a CNC-controlled manner. The control and/or regulation unit 80 is configured to control the movement of the induction heating unit 16 along the tower unit 84. The tower unit 84 comprises at least one guiding unit 62 with at least one guide rail 88 for guiding a movement of the induction heating unit 16. Preferably the guiding unit 62 comprises two guide rails 88 extending in parallel along the main extension direction 90 of the tower unit 84. This advantageously allows achieving a particularly linear movement guidance.

[0030] The shrink-clamping and/or unshrink-unclamping station 18 comprises a drive unit 34. The tower unit 84 comprises the drive unit 34. The drive unit 34 is configured to move the induction heating unit 16 of the induction heating device 10 along the axial direction 24 of the tower unit 84. The drive unit 34 is configured to generate an oscillating movement of the induction heating unit 16. The drive unit 34 is configured to move the induction heating unit 16, in particular the induction coil 20, during the induction heating process. The drive unit 34 is configured to move the induction heating unit 16, in particular the induction coil 20, in an oscillating manner during the induction heating process. The drive unit 34 is configured to generate an oscillating movement of the induction heating unit 16 relative to the tower unit 84. The drive unit 34 comprises a drive shaft 44. The drive shaft 44 is arranged at least to a large extent in the tower unit 84. The drive shaft 44 is configured for coupling with the induction heating device 10. In a state when coupled with the drive shaft 44, the induction heating unit 16 moves, in a rotation of the drive shaft 44, along the axial direction 24 upward or downward on the guide rail 88, depending on a rotation direction of the drive shaft 44. The induction heating device 10 is capable of being coupled with the drive shaft 44 via a rolling ring drive 46. Together with the drive shaft 44 the rolling ring drive 46 realizes an Uhing drive. Alternative drive units, in particular drive units differing from an Uhing drive, are conceivable.

[0031] The induction heating device 10 comprises an induction coil drive unit 36. The induction coil drive unit 36 is implemented separately from the drive unit 34 of the tower unit 84. The induction coil drive unit 36 is implemented separately from the tower unit 84. The induction coil drive unit 36 is configured to oscillatingly move the induction coil 20 relative to the induction heating device 10. The induction heating device 10 comprises a housing 48. The induction coil drive unit 36 is configured to oscillatingly move the induction coil 20 relative to the housing 48 of the induction heating unit 16. Alternatively or additionally the induction coil drive unit 36 or a further induction coil drive unit (not shown) are/is configured for rotating the induction coil 20 around a rotation axis 26 during the induction heating process. The rotation axis 26 of the induction coil 20 extends in parallel to the axial direction 24 of the tool holder 14. The induction coil 20 is configured to be moved within a limited movement range 28 during the induction heating process. The induction coil 20 is configured to oscillate within the movement range 28 during the induction heating process. The movement range 28 extends over an entire region of the tool holder 14 that is to be heated in the shrink-clamping process or in the unshrink-unclamping process. The movement range 28 extends over a clamping region 22 of the tool holder 14. The extension of the movement range 28, in particular along the axial direction 24, depends on the tool holder 14 that is to be heated, in particular from the measurements of the tool holder 14 that is to be heated and of the tool 12 that is to be fixated. The control and/or regulation unit 80 is configured to adjust the movement range 28 depending on a tool holder type and/or on a tool type.

[0032] The shrink-clamping and/or unshrink-unclamping station 18 comprises a holding device 42. The holding device 42 is configured for holding a tool holder 14 in the shrink-clamping and/or unshrink-unclamping station 18. The holding device 42 comprises a spindle unit 100. The spindle unit 100 is rotatable. The spindle unit 100 is fixedly connected with a basis unit (not shown) of the shrink-clamping and/or unshrink-unclamping station 18. The holding unit 42 comprises an attachment holder 64. The attachment holder 64 is insertable in the spindle unit 100 in an exchangeable fashion. The attachment holder 64 is configured to provide a suitable receiving region for a certain tool holder type.

[0033] FIG. 2 shows a flow chart of a method for a heating of a tool holder 14 by means of an induction heating device 10. In at least one method step 50 a tool holder 14 is inserted into the holding device 42 of the shrink-clamping and/or unshrink-unclamping station 18. If the tool holder 14 has a tool 12 fixated therein, an unshrink-unclamping process is then carried out. If the tool holder 14 does not have a tool fixated therein, a shrink-clamping process is then carried out. The method steps explained below may be implemented in similar ways in each of the two cases. In at least one method step 52 the tool holder type of the tool holder 14 inserted in the shrink-clamping and/or unshrink-unclamping station 18 is input by an operator or is automatically detected by a read-out of a coding, e.g. a QR code, a barcode or an RFID chip, or via an image recognition by a camera system. In at least one further method step 56 a length of the tool holder 14, a diameter of the tool receiving opening 40 and/or an ideal shrinking and/or clamping depth are/is determined on the basis of the identified tool holder type. In the method step 56 the region of the tool holder 14 that is to be heated is determined on the basis of the identified tool holder type. In the method step 56 the clamping region 22 is determined on the basis of the identified tool holder type.

[0034] In at least one further method step 66 the movement range 28 of the induction coil 20 is adjusted depending on the respective tool holder 14 that is to be heated, in particular depending on the clamping region 22 of the tool holder 14. In the method step 66 it is determined via the control and/or regulation unit 80 whether and to what extent the induction coil 20 needs to be moved to achieve an even heating of the entire clamping region 22. In the method step 66 the drive unit 34 and/or the induction coil drive unit 36 are/is programmed. In the method step 66 a trajectory is adjusted that is to be traveled by the induction coil 20 during the induction heating process. In at least one further method step 58 the induction coil 20 is activated for a generation of an induction magnetic field. In the method step 58 the induction heating process is started for the purpose of expanding the tool receiving opening 40 of the tool holder 14. In at least one further method step 60 the induction coil 20 is moved in an oscillating manner during the induction heating process. In the method step 60 the induction coil 20 is moved during the induction heating process along the axial direction 24 of the tool holder 14 that is to be heated. In the method step 60 the induction coil 20 is moved in such a way that the movement range 28 of the induction coil 20 completely covers a region of the tool holder 14 that is to be heated in the induction heating process. In the method step 60 the induction coil 20 is moved in such a way that the movement range 28 of the induction coil 20 completely covers the clamping region 22 of the tool holder 14. The movement range 28, within which the induction coil 20 is maximally moved in the axial direction 24 during the induction heating process, measures 20 mm in the exemplary embodiment shown. Differing maximum movement ranges 28 are conceivable. A frequency which the induction coil 20 is moved with during the induction heating process is 2 Hz in the exemplary embodiment shown. Differing frequencies are conceivable. If the clamping region 22 has an extension that is at least substantially equivalent to the extension of the induction coil 20 in the axial direction 24, it is conceivable that the induction coil 20 remains in such a case immobile during the induction heating process.

[0035] In at least one further method step 68 the induction coil 20 is rotationally moved during the induction heating process around the rotation axis 26 that extends in parallel to the axial direction 24 of the tool holder 14. In at least one further method step 70 the tool holder 14 is rotationally moved during the induction heating process around the rotation axis 26 that extends in parallel to the axial direction 24 of the tool holder 14. In at least one further method step 72, subsequently to a heating of the clamping region 22 of the tool holder 14, the clamping region 22 of the tool holder 14 is actively cooled. In the method step 72 the oscillating movement of the induction coil 20 is used for applying cooling air onto the entire previously heated clamping region 22 of the tool holder 14. In at least one further method step 82 the cooled tool holder 14 and/or the tool 12 are/is removed from the shrink-clamping and/or unshrink-unclamping station 18.