Tool changing device, machine tool with such a tool changing device and associated method

Description

[0001] The invention relates to a tool changing device with at least two tool holders for each holding a tool and with a drive device with which the tool holders can be moved into a working position relative to a frame of a machine tool and / or one of the tool changing devices.

[0002] The invention further relates to a machine tool with such a tool changing device and a method for changing tools on a machine tool using a tool changing device.

[0003] Such tool-changing devices, machine tools, and also methods for changing tools are known in various forms from the prior art. The ability to lock the tool plays a particularly important role in high-precision machining operations. The tool-changing devices known from the prior art utilize motor-driven drive mechanisms that allow the tool holders to be adjusted to the desired position. Once the desired position of the tool holder is reached, the tool holder is locked in its current position by means of a locking element, which is advanced by another drive, so that the workpiece can then be machined.Therefore, both a drive device and a locking device must be kept ready, which represents a comparatively large effort because these devices each have their own drives.

[0004] The object of the invention is therefore to provide a tool changing device, a machine tool and a method of the type mentioned at the outset, in which the effort for positioning the tool holders in a working position and for locking them in the working position can be reduced.

[0005] This object is achieved by a tool-changing device of the type mentioned at the outset, having the means and features of the independent claim directed to a tool-changing device. In particular, to achieve this object, in a tool-changing device of the type mentioned at the outset, it is proposed that the drive device comprise at least one locking element and at least one counter-element connected at least indirectly to the at least two tool holders, wherein the tool holders are positioned in a working position and locked there by a relative adjustment movement between the locking element and the counter-element. The tool holders are locked when the locking element and counter-element are arranged relative to one another in the locked position.

[0006] The core of the invention thus lies in the idea of ​​designing the tool-changing device in such a way that an adjustment movement required to lock the tool holders, which is carried out by a locking element and / or a counter-element relative to one another, is used to position the tool holders in a working position. In other words, the tool-changing device is thus configured to effect a positioning of the tool holders in the working position through the locking action.

[0007] Thus, the tool changing device according to the invention eliminates the need for a separate drive for adjusting the tool holders to their working position. This is advantageous because it reduces both the required installation space and the energy required to adjust and lock the tool holders.

[0008] The locking element and the counter element can preferably interact mechanically in such a way that an adjustment movement of the locking element relative to the counter element into its locking position can be converted into a positioning movement of the counter element. This positioning movement allows the tool holders to move into the working position and be secured with the aid of the locking element, which is ultimately in the locked position on the counter element. In this case, the counter element can serve as a force transmission element, via which the drive force of the locking element can be transmitted to the tool holders for positioning them in the working position.

[0009] However, it is also possible for the locking element and the counter-element to interact, preferably mechanically, in such a way that an adjustment movement of the counter-element carried out relative to the locking element into a locking position on the locking element can be converted into a positioning movement of the counter-element, by means of which the tool holders can be positioned in a working position.

[0010] Preferably, the locking element and the counter-element can interact mechanically in such a way that a linear adjustment of the locking element or the counter-element causes a rotational positioning movement of the counter-element. The linear adjustment of the locking element is achieved by an adjustment movement of the locking element into the locking position, carried out relative to the counter-element. The linear adjustment of the counter-element is achieved by an adjustment movement of the counter-element into the locking position, carried out relative to the locking element. The rotational positioning movement of the counter-element can take place into a position corresponding to the working position. In this way, the tool changing device can be used, for example, in tool turrets on machine tools. In this context, it can be advantageous if the counter-element is rotatably mounted on the base body of the tool changing device.

[0011] The positioning movement that can be transmitted by the locking element to the at least two tool holders and / or to a tool head on which the at least two tool holders can be formed can be a linear movement or a rotary movement. A rotary positioning movement can occur around a rotational axis of the tool head. The tool holders can rotate along a closed path around the rotational axis.

[0012] An adjustment movement that can be carried out with the locking element for adjustment can preferably be a linear movement, but if necessary also a rotational movement.

[0013] The conversion of the adjustment movement of the locking element into a positioning movement of the tool holders can be achieved in a comparatively simple manner if the at least one counter-element has a tooth profile or claw profile corresponding to the at least one locking element. The tooth profile or claw profile can be configured to correspond to the locking element in such a way that engagement of the locking element with the tooth profile or claw profile of the counter-element causes rotation of the counter-element.

[0014] The conversion of the adjustment movement of the locking element into a rotation of the counter element can be achieved with virtually no loss if the counter element remains stationary in the axial direction, i.e., if the locking element is not axially displaced but only rotated by the adjustment. Thus, the locking element and the counter element form a type of gear stage with which a first movement, the adjustment movement, can be converted into a second movement, the positioning movement. Furthermore, the counter element is locked by this gear stage when at least one of the tool holders has assumed its working position and the locking element has assumed its locking position.

[0015] Particularly preferably, the locking element and the counter element have corresponding tooth or claw profiles. The teeth or claw projections of the tooth or claw profiles are preferably evenly distributed around a rotational axis of the counter element.

[0016] The tool holders can be connected to the counter element in such a way that relative movement between the tool holders and the counter element is prevented and thus excluded. In other words, the tool holders and the counter element can be connected to each other in a rotationally fixed manner. In this way, any movement of the counter element caused by the locking element can be reliably transmitted to the tool holders.

[0017] The tool changing device can have a tool head. The at least two tool holders can be arranged or formed on this tool head. Furthermore, it is possible to move, in particular rotate, the tool head relative to the frame and / or the base body of the tool changing device.

[0018] In one embodiment of the tool changing device, it can be provided that the locking element is arranged on the frame or the base body, and the counter element is arranged on a movable tool head, for example, the previously mentioned one. It is also possible for the locking element to be arranged on a movable tool head, for example, the previously mentioned one, and the counter element to be arranged on the frame.

[0019] In a particularly preferred embodiment of the tool changing device, the locking element is designed as an axially fixed claw element, preferably rotationally fixed or non-rotatable relative to the base body of the tool changing device, and the counter element is designed as a rotatable counter claw element that is axially displaceable with respect to its rotational axis. Both the locking element and the counter element then each have at least one claw flank that is inclined to the rotational axis of the counter element. The claw flanks of the two claw elements are designed to correspond to one another and can have engagement surfaces that are inclined to the rotational axis of the counter element, so that by adjusting the counter element into its locking position on the locking element, a drive force can be transmitted to the counter element via the claw flanks and their engagement surfaces.

[0020] The locking element designed as a claw element and the counter element designed as a counter claw element form a type of claw coupling in the locking position.

[0021] Furthermore, it may be advantageous if the tool changing device has an adjusting device. With such an adjusting device, an adjusting force can be transmitted, at least indirectly, preferably via the counter element, to the tool holders. The adjusting force can also be transmitted to a tool head, in particular to one of the type described above, on which the tool holders can also be formed.

[0022] The adjusting device can be configured to automatically move the tool holders from the working position to an intermediate or rest position using the adjusting force. The counter element can be moved from a position corresponding to the working position to an engaged position by the adjusting force. This is particularly the case when the adjusting device acts on the counter element. In this engaged position, the counter element can be arranged such that the locking element can be brought back into engagement with the counter element, or vice versa, in order to subsequently adjust another of the at least two tool holders into a working position using the locking element.In this way, a tool changing device is created in which the counter element automatically moves into an engagement position with the aid of the adjusting device as soon as the locking of the counter element is released by the locking element and the counter element is released or not locked.

[0023] The counter element can thus automatically move from a position into an engagement position in which none of the tool holders is arranged in the working position anymore and in which a renewed engagement and a renewed actuation of the counter element for positioning at least one of the tool holders in a working position is possible with the aid of the locking element.

[0024] The magnitude of the actuating force can depend on the relative position of the locking element and the counter-element. When the locking element is in the locked position, the actuating force can act in the direction of a positioning movement of the tool holders, for example, as already mentioned. It can be particularly advantageous if the actuating force reaches a maximum when the locking element is in its locked position and at least one of the tool holders is in its working position. In this way, it can be ensured that the counter-element, together with the tool holder, can be moved further with sufficient actuating force due to the actuating force acting in the direction of the positioning movement as soon as the locking element has released the counter-element again.

[0025] Furthermore, the actuating force can act and be oriented alternately in the direction and opposite to the direction of a positioning movement of the tool holders, in particular of the counter-element, in successive relative positions. In this way, the actuating device can be used to effect the automatic positioning or further positioning of the counter-element and the tool holders relative to the locking element into a specific intermediate position or engagement position. Due to the actuating force vectors directed opposite to one another with respect to two successive relative positions, the actuating device can effect a centering of the tool holders in an intermediate position and / or of the counter-element in an engagement position, in which the locking element can engage with the counter-element again in a further actuation step. Particularly preferably, the actuating force can be at a minimum when the counter-element is in the engagement position.To reliably hold the counter-element in the engaged position, it may also be advantageous if the adjusting device is configured to generate a holding force, preferably radial, acting on the counter-element. This holding force can reach a maximum when the counter-element is arranged in an engaged position.

[0026] The adjusting device can be arranged or formed between the frame or a base body of the tool changing device and the counter element with the at least two tool holders. The adjusting device can particularly preferably be designed as a magnetic adjusting device. In a magnetic adjusting device with permanent magnets, an energy supply to the adjusting device is unnecessary. If the adjusting device is designed as a magnetic adjusting device, it can comprise at least one magnet fixed relative to the counter element and at least one counter magnet arranged on the counter element to generate the adjusting force. With the at least one magnet and the at least one counter magnet, the counter element can be brought into an engaged position, in particular when the locking element is no longer in engagement with the counter element.

[0027] In a particularly preferred embodiment of the tool changing device, the magnetic actuating device can comprise several, preferably four, individual magnets, which are evenly distributed on a retaining ring with a corresponding polarity alignment, in particular around a rotational axis of the counter-element. The counter-element can in turn be equipped with an equal number of correspondingly arranged counter-magnets. When the counter-element is in the use position, the magnets and the counter-magnets can generate the previously described actuating force and / or holding force of the actuating device through mutual attraction and automatically move the counter-element into an engaged position in which it is ready for renewed engagement of the locking element in order to reposition the tool holders.

[0028] It can be particularly advantageous if the number of magnets and the number of counter-magnets correspond to a number or an integer multiple of the number of individual tool holders of the tool changing device. This allows the counter element to be moved into a separate engagement position for each tool holder using the magnetic adjustment device, in which, for example, no tool holder is arranged in a working position.

[0029] A spring-operated actuator or an actuator with a ball-lock mechanism can also be used as the actuator.

[0030] The drive device may include a drive for adjusting the locking element. This drive may preferably be electric, pneumatic, hydraulic, or even electromagnetic.

[0031] It can be particularly advantageous if the drive device is a drive device of a machine tool for generating a tool feed. In this way, the drive device can perform a dual function and also effect the tool change movement.

[0032] The above-mentioned object is also achieved by a machine tool with a tool changing device according to one of the claims directed to the tool changing device.

[0033] In this context, it can be advantageous if the machine tool has a drive device configured to generate a tool feed and the relative adjustment movement between the locking element and the counter element. An additional drive for the tool change process is thus unnecessary. Preferably, the tool feed is synchronized with the workpiece rotation, for example, to enable the production of non-circular workpieces. It is advantageous if the adjustment movement and the tool feed are aligned parallel to each other, for example, along the same straight line.

[0034] In order to switch between adjustment mode and feed mode, the machine tool can have a locking device, in particular with a locking plunger. This locking device can fix the locking element of the tool-changing device relative to a frame of the machine tool and / or relative to the counter element, at least during a tool change.

[0035] To achieve this objective, a method for changing a tool using a tool-changing device, in particular one according to one of the claims directed to the tool-changing device, is also proposed, in which a tool holder of the tool-changing device carrying the tool is positioned into a working position by a relative adjustment movement between a locking element and a counter-element of the tool-changing device. In this way, the locking element, which is particularly necessary for high-precision machine tools, can assume a dual function, not only locking the tool holders but also positioning them in a working position.

[0036] The locking element can be moved to position the tool holder into a locking position that locks the counter element. However, it is also possible to move the counter element into a locking position relative to the locking element to position the tool holder. The adjustment movement can be converted into a positioning movement of the counter element. One of the tool holders can then be locked in its working position when the locking element and / or the counter element reach the locking position.

[0037] After the locking element and / or the counter-element have been disengaged from the locking position, the tool holder can be adjusted from the working position to an intermediate position. Furthermore, the released, i.e., no longer locked, counter-element can be moved from a position corresponding to the working position to an engaged position, in which the counter-element and the tool holder can be re-locked. Both can preferably occur automatically after the locking element and / or the counter-element have been disengaged from the locking position. The automatic adjustment of the tool holder and / or the counter-element can be effected by means of an adjusting device. An adjusting device can be used, for example, as described in more detail in one of claims 9 to 12.

[0038] Once the tool holder has been moved into its working position, the tool can be used to perform a machining operation, such as turning, milling, and / or grinding on a workpiece. This can be synchronized with the workpiece rotation—particularly for the production of non-circular turned parts in a single setup. The clamping operation can also be performed before the tool change.

[0039] An embodiment of the invention is described in more detail below with reference to the drawings, which show, in some cases, highly schematic representations: Fig. 1 a perspective view of a machine tool according to the invention with a tool changing device with several tool holders, Fig. 2 a perspective view of the in Figure 1 shown tool changing device, Fig. 3 a perspective view of the Figures 1 and 2shown tool changing device, where here a counter element of the tool changing device with a carrier plate for the Figures 1 and 2 shown tool head can be seen, Fig. 4 a side view of the Figures 1 to 3 illustrated tool changing device, wherein the counter element with its (counter) claw profile and the locking element cooperating with the counter element with a claw profile corresponding to the claw profile of the counter element can be seen, Fig. 5 a cross section of the tool changing device along the Figure 4 line marked AA, Fig. 6a a cross section of the tool changing device along the line BB in Figure 6b with the locking element in the locking position, Fig. 6 legs to Fig. 6acorresponding side view of the tool changing device shown in the previous figures with engaged claw profiles, Fig. 7a a cross section of the tool changing device along the Figure 7b line marked CC, Fig. 7b, which leads to Figure 7acorresponding side view of the tool changing device, wherein the locking element is shown in its initial position in which it is not in engagement with the claw profile of the counter element, Fig. 8a and 8b cross-section and a side view of the tool changing device shown in the previous figures, wherein the counter element has assumed its engagement position due to the effect of the adjusting device, in which the counter element is arranged relative to the locking element such that the locking element can again engage with the claw profile of the counter element for further positioning of the tool holders, Fig. 9a to 10b further cross-sections and side views of the tool changing device shown in the previous figures, wherein in Figure 9bthe locking element in an intermediate position on its way to the locking position and the counter element in a corresponding intermediate position on its way of one of the tool holders into its locked working position, while the counter element in the Figures 10a and 10b a position corresponding to the working position of one of the tool holders and the locking element has completely reached its locking position, as well as Figs. 11 to 16 side views of a machine tool according to the invention with a tool changing device according to the invention for illustrating a tool changing process using the drive device of the machine tool.

[0040] All figures show a tool changing device designated as a whole by 1. The tool changing device 1 is used at the at least partially shown Figure 1 and 11 to 16 The machine tool 18 shown is used. The remaining Figures 2 to 10bshow different views of the tool changing device 1.

[0041] The tool changing device 1 is equipped with a tool head 23. A total of four tool holders 2 are formed on the tool head 23, arranged offset by 90 degrees to one another. A tool 3 is arranged on each tool holder 2. The tool changing device 1 has a drive device 4, with which the tool holders 2 are moved into a working position relative to a frame 5 of the machine tool 18 and also relative to a base body 5a of the tool changing device 1. The working position is in Figure 1 illustrated by the dashed line marked 6.

[0042] The drive device 4 comprises a locking element 7 and a counter element 8. The tool head 23 with the tool holders 2 is connected to the counter element 8. The locking element 7 and the counter element 8 interact mechanically in such a way that the total of four tool holders 2 on the tool head 23 can be positioned one after the other in the working position 6 and fixed there with the locking element 7. The positioning of the tool holders 2 takes place in the embodiment shown in the figures by the counter element 8 in its, for example, Figure 10a locking position marked with the reference number 9 is moved relative to the locking element 7.

[0043] During this adjustment, the locking element 7 interacts mechanically with the counter element 8 in such a way that a linear adjustment movement of the counter element 8 into its locking position 9, which is indicated by the arrow 22 in the Figures 9b and 10bis illustrated, a positioning movement of the counter element 8 in the direction of the arrow 21 ( Figures 9a and 9b ) is caused.

[0044] The counter element 8 assumes a position or relative position corresponding to the working position 6 of the tool holders 2. This corresponding position or relative position of the counter element 8 is shown in the Figures 6a and 6b as well as 10a and 10b.

[0045] The positioning movement 21, which can be transmitted to the tool holders 2 on the tool head 23 by means of the locking element 7 and the counter element 8, is a rotary movement that occurs about a rotational axis R of the tool head 23 and the counter element 8. The adjustment movement 22, which can be performed with the counter element 8, is a linear movement that occurs in the direction of the rotational axis R of the tool head 23 and the counter element 8 relative to the axially fixed locking element 7.

[0046] The counter element 8 has a claw profile 10. The locking element 7 has a corresponding claw profile 10. Thus, when the counter element 8 engages in the claw profile 10 of the locking element 7, a rotation of the counter element 8 can be effected. The locking element 7 remains stationary in the axial direction due to its bearing 19 on the base body 5a of the tool changing device 1, i.e., it is axially fixed with respect to the rotation axis R. This is apparent when comparing the different positions of the locking element 7, which are shown in the Figures 2 to 10b and especially 11 to 16 are shown, clearly.

[0047] The tool holders 2 are connected to the counter element 8 via the tool head 23 in such a way that relative movement between the tool holders 2 and the counter element 8 is prevented. The tool holders 2 are connected to the counter element 8 in a rotationally fixed manner via the tool head 23.

[0048] In particular, the Figures 3 and 4show that the counter element 8 comprises a carrier plate 11 at its end facing the tool head 23 in the use position. The tool head 23 is fastened to the counter element 8 in the use position via this carrier plate 11. A torque which is transmitted from the locking element 7 to the counter element 8 can be transmitted via the carrier plate 11 to the tool head 23 and the tool holders 2 formed thereon, in order to be able to move the tool holders 2 one after the other into their desired working position 6. The carrier plate 11 serves to conveniently fasten the tool head 23 to the counter element 8. By being fixed to the rotatably mounted counter element 8, the tool head 23 of the tool changing device 1 is rotatable relative to the frame 5 of the machine tool 18 and also relative to the base body 5a of the tool changing device 1.

[0049] The locking element 7 is arranged on the base body 5a. The counter element 8 is arranged on the side with the movable tool head 23. The base body 5a has an external holder 5b, visible in the figures. This holder 5b serves to attach a glass scale (not shown), with which a movement of the base body 5a relative to a frame 5 of the machine tool 18 can be monitored.

[0050] A circumferential flange 5c is used to fasten the base body 5a to a corresponding counterpart of the machine tool 18.

[0051] The counter element 8 is a counter claw element 12 on which one of the previously mentioned claw profiles 10 is formed. The locking element 7 is designed as a claw element 13 that is axially fixed with respect to the rotation axis R and relative to the counter element 8, which in turn has the further, previously mentioned claw profile 10 and is also rotationally fixed relative to the base body 5a. The locking element 7 designed as a claw element 13 is similar in function to an axially fixed claw jaw that is not axially displaced with respect to the rotation axis R during the changing process, whereas the counter element 8 designed as a counter claw element 12 is similar to an axially displaceable claw sleeve. Thus, in this exemplary embodiment, the counter element 8 is displaced during the changing process relative to the locking element 7, which is static at least during the changing process.

[0052] The locking element 7 and the counter element 8 have matching engagement surfaces 14 on the claw flanks 15 of their claw profiles 10. The engagement surfaces 14 and the claw flanks 15 are aligned obliquely to the rotation axis R. The inclined position of the engagement surfaces 14 allows a drive force of the counter element 8 to be redirected and the axial adjustment movement 22 of the counter element 8 to be converted into the rotary positioning movement 21 of the counter element 8. Due to their inclined position, the engagement surfaces 14 and the claw flanks 15 determine the direction of rotation of the positioning movement 21.

[0053] Both the locking element 7 and the counter element 8 each have a total of four claw projections 15a with claw flanks 15. The claw projections 15a and claw flanks 15 are arranged offset by 90 degrees from one another around the rotation axis R of the counter element 8. Thus, the locking element 7 can move the counter element 8 into four different positions and secure it there. The arrangement of the claw projections 15a and claw flanks 15 corresponds to the arrangement of the tool holders 2. Furthermore, the number of inclined claw flanks 15 provided on the locking element 7 corresponds to the number of inclined claw flanks 15 provided on the counter element 8 and also to the number of tool holders 2. In addition, four claw projections 15a are formed on the locking element 7 and four (counter) claw projections 15a on the counter element 8.

[0054] The tool changing device 1 further comprises an adjusting device 16. This adjusting device 16 serves to automatically advance the counter element 8 when it is released by the locking element 7. This is done with the aim of enabling renewed engagement of the locking element 7 with the counter element 8 for positioning a next tool holder 2 in the working position 6 and finally for locking the counter element 8 and the positioned tool holder 2.

[0055] For this purpose, the actuating device 16 is configured to generate an actuating force that can be transmitted via the counter-element 8 to the tool head 23 and the tool holders 2. The actuating force is used to automatically move each of the four tool holders 2, and in particular the counter-element 8, from the working position 6 into an intermediate position when the counter-element 8 is moved from the locking position 9. In this intermediate position, the counter-element 8 is arranged in an engagement position 17 relative to the locking element 7.

[0056] The engagement position 17 is based on the Figure 8a dashed line. In this engagement position 17, the counter element 8 can be moved by an axial adjustment, as shown in the Figures 9a and 9b can be seen, be brought into engagement with the locking element 7 again in order to carry out the positioning of the next one of the tool holders 2 into the working position 6 (cf. Fig. 6a and 6bas well as 10a and Fig. 10b ).

[0057] The magnitude of the actuating force applied by the actuating device 16 depends on the relative position of the counter-element 8 to the locking element 7. Thus, the actuating force decreases in a relative position of the counter-element 8 to the locking element 7 corresponding to the working position 6, i.e., when the counter-element 8 is fixed by the locking element 7 ( Figures 6a and 6b and 10a and 10b), a maximum value. In this way, it can be ensured that the actuating force acting to further move the tool holders 2 and ultimately also the counter element 8 in the direction of the positioning movement of the tool holders 2 indicated by the arrow 21 is sufficient to further move the counter element 8 together with the tool holders 2 into the engagement position 17 after release by the locking element 7.

[0058] The aforementioned actuating force acts in successive relative positions of the counter-element 8 to the locking element 7 alternately in the direction and against the direction of the positioning movement 21 of the tool holders 2 and assumes the value zero in the engaged position 17. This has the consequence that the counter-element 8 released by the locking element 7 assumes a stable intermediate position due to the actuating force of the actuating device 16. In Figure 8a The counter element 8 and the adjusting device 16 are shown in such an intermediate position between two successive relative positions. This intermediate position corresponds to the previously mentioned engagement position 17.

[0059] In the engaged position 17, the adjusting device 16 applies a holding force with which the counter element 8 is held in its engaged position 17 for renewed engagement of the locking element 7. Regardless of the direction in which the counter element 8 is moved from this engaged position 17, the adjusting device 16 automatically applies an actuating force acting in the opposite direction and toward the engaged position 17.

[0060] The adjusting device 16 is formed between the base body 5a of the tool changing device 1 and the counter element 8, which is rotatable relative to the base body. The adjusting device 16 is a magnetic adjusting device and has a retaining ring 20 with four magnets 20a arranged evenly distributed around the rotational axis R of the counter element 8. The counter element 8 is rotatably mounted in the base body 5a of the tool changing device 1 via two bearings 19. The base body 5a of the tool changing device 1 can therefore also be referred to as a housing.

[0061] The retaining ring 20 with the magnets 20a surrounds the counter element 8 in the use position on the outside and is fixed to the base body 5a of the tool changing device 1. Four counter magnets 20b are arranged on the counter element 8, evenly distributed around the rotation axis R of the counter element 8, which are assigned to the magnets 20a on the retaining ring 20 and are also part of the magnetic actuating device 16. The magnets 20a and the counter magnets 20b are arranged with regard to their polarity such that they are in the Figure 8a In the engagement position 17 shown, the counter element 8 attracts each other to the locking element 7, thus ensuring a stable position of the counter element 8 in this engagement position 17. In the engagement position 17, the magnets 20a and the counter magnets 20b build up a radially acting holding force due to their mutual attraction and polarity.

[0062] If the magnets 20a and counter magnets 20b are removed from the Figure 8When the counter-element 8 is rotated relative to the stationary retaining ring 20, the magnets 20a and counter-magnets 20b build up the actuating force acting in the direction of the engagement position 17. This actuating force has at least a tangential component and must be overcome by the counter-element 8 for positioning the counter-element 8 by its axial advance toward the locking element 7.

[0063] The actuating force applied by the magnets 20a and counter-magnets 20b is smaller than the force applied by the counter-element 8, which is converted into a positioning force via the claw flanks 15 of the claw-like locking element 7 and the claw-like counter-element 8. Thus, the actuating force of the actuating device 16 can be overcome with the aid of the counter-element 8, and the counter-element 8 can be rotated further to move a subsequent tool holder 2 into the working position 6. The counter-element 8 can thus be referred to as a rotary slide valve, with which an axial actuating movement of the counter-element 8 can be converted into a rotary positioning movement 21 of the counter-element 8.

[0064] The four tool holders 2 on the tool head 23 are each assigned a magnet 20a and a counter magnet 20b, so that the adjusting device 16 has a total of four magnets 20a and four magnets 20b, which are each distributed offset by 90 degrees to one another around the rotation axis R of the counter element 8.

[0065] The drive device 4 comprises a drive for axially adjusting the locking element 7. This drive is part of the drive device 4 of the machine tool 18 and is designed as an electromagnetic drive device 4, with which lifting movements can be performed at high frequencies.

[0066] Thus, the machine tool 18 has a drive device 4 configured to generate a tool feed and the adjustment movement 22 between the locking element 7 and the counter element 8. A separate drive device for the adjustment movement for tool change is therefore not necessary.

[0067] The machine tool 18 further comprises a locking device 24 with a locking plunger 25. With the aid of the locking device 24 and the locking plunger 25, the locking element 7 of the tool changing device 1 can be fixed relative to the frame 5 of the machine tool 18, at least during a tool change. For this purpose, the locking plunger 25 is inserted into a corresponding recess 26 on the locking element 7. In this, for example, in Fig. 13 In the position shown, the locking plunger 25 holds the locking element 7 and ensures that, upon a corresponding feed movement of the drive device 4 of the machine tool 18, the counter element 8 is released from the locking element 7 in order to carry out the tool change as described in detail above.

[0068] In order to prevent an unintentional release of the counter element 8 from the locking element 7 during a high-frequency oscillating feed movement of the drive device 4, a compression spring 27 is provided which holds the locking element 7 in its locking position on the counter element 8.

[0069] Fig. 11 shows the machine tool 18 in operating mode. In operating mode, the locking plunger 25 is disengaged and the locking element 7 is freely movable by the drive device 4 of the machine tool 18. In operating mode, the drive device 4 serves as a feed drive for the tool head 23 with the tools 3 arranged thereon.

[0070] In Fig. 12 the tool head 23 is compared to Fig. 11retracted. The locking element 7 is now arranged relative to the locking device 25 such that the locking plunger 25 can be inserted into the recess 26 on the locking element 7. The locking plunger 25 is moved pneumatically and / or hydraulically for this purpose.

[0071] In Fig. 13 The locking plunger 25 is retracted into the recess 26. This fixes the locking element 7 relative to the locking plunger 25 and the frame 5 of the machine tool 18. The machine tool 18 is now in tool change mode. The drive device 4 of the machine tool 18 now serves as the tool change drive.

[0072] In Fig. 14The tool head 23 is moved forward by means of the drive device 4. Since the locking element 7 is fixed by the locking plunger 25, the counter element 8 and the locking element 7 are released from each other by the linear adjustment movement 22 caused by the drive device 4. As soon as the counter element 8 is completely released from the locking element 7, the adjusting device 16 can rotate the counter element 8 relative to the locking element 7 into the engagement position 17 and initiate the tool change.

[0073] In Fig. 15 The tool head 23 with the counter element 8 was moved back to its rear position by the drive device 4. Via the engagement surfaces 14 on the claw flanks 15, the linear return movement of the tool head 23 was converted into the positioning movement 21, and the tool 3 was changed.

[0074] In Fig. 16The locking plunger 25 is retracted from the recess 26 of the locking element 7. The locking element 7 is pressed back against the counter element 8 by the spring 27. The counter element 8 is locked by the locking element 7. The tool change is complete. The machine tool 18 is back in operating mode, and the drive device 4 of the machine tool 4 can be used to generate a feed movement.

[0075] With the tool changing device 1 described above, the method described below for changing a tool 3 on the machine tool 18 can be carried out.

[0076] In this process, a tool holder 2 of the tool changing device 1, which carries the tool 3, is positioned in a working position 6 by moving the counter element 8 of the tool changing device 1 into a locking position 9 on the locking element 7. To position the tool holder 2, the counter element 8 engages in the locking element 7 and is moved relative to it.

[0077] As already explained above, the tool holders 2 and the counter element 8 are connected to one another in a rotationally fixed manner. In general, one could also say that the tool holders 2 and the counter element 8 are connected to one another in such a way that a relative movement between them is excluded. As soon as the counter element 8 reaches its locking position 9 on the locking element 7, the tool holder 2 reaches the working position 6 and is fixed in this position by the locking element 7. As soon as the counter element 8 is released from its locking position 9 ( Figures 6a and 6b , 10a and 10bas well as Fig. 14 ) is disengaged again, the tool holder 2 is automatically moved away from the working position 6 and the counter element 8 is adjusted to an engagement position 17. This is done by means of the previously described adjusting device 16. During positioning, the tool holders 2 move along a closed, circumferential path. Thus, a full revolution of the path is necessary before a tool holder 2 reaches the same working position 6 again.

[0078] The invention relates to improvements in the field of so-called tool changing devices 1 used on machine tools 18. Provision is made here for positioning a tool holder 2 into its working position 6 with the aid of the locking element 7 of the drive device 4 of the tool changing device 1. An adjustment movement 22 of the locking element 7 into its locking position 9 required for use of the tool 3 is used to position the tool holder 2 in its working position 6 by converting the adjustment movement 22 of the locking element 7 into a positioning movement 21 of the tool holder 2. List of reference symbols

[0079] 1Tool changing device 2Tool holders 3Tool 4Drive device 5Frame 5aBase body of 1 5bHolder 5cFlange 6Working position 7Locking element 7aGuide element on 7 8Counter element 9Locking position 10Claw profile 11Carrier plate 12Counter claw element 13Claw element 14Engagement surface 15Claw flank 15aClaw projections on 7 and 8 16Adjusting device 17Engagement position 18Machine tool 19Bearing 20Retaining ring 20aMagnet 20bCounter magnet 21Positioning movement 22Adjusting movement 23Tool head 24Locking device 25Locking plunger 26Recess 27Compression spring RRotation axis of 8

Claims

1. Tool changing device (1) having at least two tool holders (2) for holding one tool (3) each and having a drive device (4) which comprises at least one locking element (7), at least one counter element (8) connected at least indirectly to the at least two tool holders (2), and a drive for producing a linear adjustment movement (22), wherein the tool holders (2) are movable relative to a frame (5) and / or a base body (5a) of the tool changing device (1) by means of a rotary positioning movement (21) of the counter element (8) about a axis of rotation R into a working position (6), wherein the locking element (7) and the counter element (8) are adjustable relative to each other by the linear adjustment movement (22) generated by the drive, which takes place in the direction of the axis of rotation R, and wherein the counter element (8) and the locking element (7) interact in such a way that the linear adjustment movement (22) is converted into the rotary positioning movement (21), so that the tool holders (2) are positioned in the working position (6) by the linear relative adjustment movement (22) between the locking element (7) and the counter element (8) and are locked there.

2. Tool changing device (1) according to claim 1, characterized in that the locking element (7) and the counter element (8) interact, preferably mechanically, in such a way that an adjustment movement (22) of the locking element (7) relative to the counter element (8) is converted into a locking position (9) and / or in that an adjustment movement (22) of the counter element (8) relative to the locking element (7) into a locking position (9) on the locking element (7) is converted into the positioning movement (21) of the counter element (8), by means of which the tool holders (2) can be positioned in the working position (6).

3. Tool changing device (1) according to claim 1 or 2, characterized in that the positioning movement (21) of the counter element (8) is a rotary movement about a rotation axis of the tool head (23), preferably wherein the tool holders (2) rotate along a closed path about the axis of rotation (R).

4. Tool changing device (1) according to one of the preceding claims, characterized in that the at least one counter element (8) has a tooth profile and / or claw profile (10) designed to correspond to the at least one locking element (7), preferably wherein the locking element (7) and the counter element (8) have corresponding tooth profiles and / or claw profiles (10).

5. Tool changing device (1) according to one of the preceding claims, characterized in that the tool holders (2) are connected to the counter element (8) in such a way that a relative movement between the tool holders (2) and the counter element (8) is prevented, in particular wherein the tool holders (2) are connected to the counter element (8) in a rotationally fixed manner.

6. Tool changing device (1) according to one of the preceding claims, characterized in that the tool changing device (1) has a tool head (23) on which the at least two tool holders (2) are arranged or formed and which is movable, in particular rotatable, relative to the frame (5) and / or to the base body (5a) of the tool changing device (1).

7. Tool changing device (1) according to one of the preceding claims, characterized in that the locking element (7) is arranged on the frame (5) and / or on the base body (5a) and the counter element (8) is arranged on one or the movable tool head (23), or in that the locking element (7) is arranged on one or the movable tool head (23) and the counter element (8) is arranged on the frame (5).

8. Tool changing device (1) according to one of the preceding claims, characterized in that the locking element (7) is designed as an axially fixed claw element (13) relative to the counter element (8) and the counter element (8) is designed as a rotatable counter-claw element (12) that can be axially displaced relative to its axis of rotation (R) and / or relative to the counter element (8), and each has at least one claw flank (15) inclined relative to the axis of rotation (R) of the counter element (8), wherein the claw flanks (15) are designed to correspond to one another so that the adjustment movement (22) can be transmitted via the claw flanks (15) into a rotary positioning movement (21) of the counter element (8).

9. Tool changing device (1) according to one of the preceding claims, characterized in that the tool changing device (1) has an actuating device (16) by means of which an actuating force can be transmitted, at least indirectly, to the tool holders (2), in particular via the counter element (8), wherein the non-locked counter element (8) together with the tool holders (2) can be automatically positioned or moved further by means of the actuating force from the working position (6) into an engagement position (17) in which the locking element (7) can be brought back into engagement with the counter element (8) or vice versa.

10. Tool changing device (1) according to claim 9, characterized in that a magnitude of the actuating force depends on a relative position of the locking element (7) and the counter element (8) relative to each other, preferably wherein the actuating force acts in the direction of one or the positioning movement (21) of the tool holders (2) when the locking element (7) is in the locking position, and particularly preferably wherein the actuating force assumes a maximum value when the locking element (7) is in the locking position.

11. Tool changing device (1) according to claim 9 or 10, characterized in that the actuating force assumes a minimum, preferably zero, when the counter element (8) is in the engagement position (17), and otherwise acts in the direction or opposite to the direction of a positioning movement (21) of the tool holders (2), preferably wherein a holding force of the actuating device (16) acting on the counter element (8), in particular a radial holding force, assumes a maximum value when the counter element (8) is in the engagement position (17).

12. Tool changing device (1) according to one of claims 9 to 11, characterized in that the actuating device (16) is arranged between the frame (5) or the base body (5a) of the tool changing device (1) and the counter element (8) and / or is designed as a magnetic actuating device (16), in particular wherein the actuating device (16) for generating the actuating force and / or a holding force comprises at least one magnet (20a) fixed relative to the counter element (8) and at least one counter magnet (20b) arranged on the counter element (8), with which the counter element (8) can be brought into an engagement position (17).

13. Tool changing device (1) according to one of claims 1 to 12, characterized in that the drive device (4) has a drive, preferably electric and / or electromagnetic and / or pneumatic and / or hydraulic, for generating the adjustment movement (22), in particular wherein the drive device (4) is a drive device of a machine tool (18) for generating a tool feed.

14. Machine tool (18) having a tool changing device (1) according to one of claims 1 to 13.

15. Machine tool (18) according to claim 14, characterized in that the machine tool (18) has a drive device (4) which is designed to generate a tool feed, preferably synchronized with workpiece rotation, and the adjustment movement (22) between the locking element (7) and the counter element (8), preferably parallel to the tool feed, and / or in that the machine tool (18) has a locking device (24), in particular with a locking tappet (25), by means of which the locking element (7) of the tool changing device (1) can be fixed relative to a frame (5) of the machine tool (18) at least during a tool change.

16. Method for changing a tool (3) using a tool changing device (1) - having at least two tool holders (2) for holding one tool (3) each and having a drive device (4) which comprises at least one locking element (7), at least one counter element (8) connected at least indirectly to the at least two tool holders (2), and a drive for generating a linear adjustment movement (22), characterized in that - the drive device (4) is used to move the tool holders (2) relative to a frame (5) and / or a base body (5a) of the tool changing device (1) by means of a rotary positioning movement (21) of the counter element (8) about an axis of rotation R into a working position (6), - wherein for this purpose the locking element (7) and the counter element (8) are displaced relative to each other by the linear adjustment movement (22) generated by the drive and performed in the direction of the axis of rotation R, and - wherein the counter element (8) and the locking element (7) interact in such a way that the linear adjustment movement (22) is converted into the rotary positioning movement (21), so that one of the tool holders (2) which carries the tool (3) is positioned in a working position (6) by the relative linear adjustment movement (22) between the locking element (7) and the counter element (8).

17. Method according to claim 16, characterized in that the locking element (7) is moved into a locking position (9) locking the counter element (8) in order to position the tool holder (2), and / or in that the counter element (8) is moved into a locking position (9) in order to position the tool holder (2), wherein the adjustment movement (22) is converted into a positioning movement (21) of the counter element (8), preferably wherein the tool holder (2) is fixed in the working position (6) when the locking element (7) and / or the counter element (8) reaches its locking position (9).

18. Method according to claim 16 or 17, characterized in that the tool holder (2), in particular the counter element (8), is moved from the working position (6) into an intermediate position or engagement position (17), preferably automatically, after the locking element (7) or the counter element (8) has been disengaged from the locking position (9).

19. Method according to one of claims 16 to 18, characterized in that the tool holder (2), in particular the counter element (8), is moved from the working position (6) into an intermediate position or engagement position (17) by means of an actuating device (16), preferably an actuating device (16) as described in one of claims 9 to 12.

20. Method according to one of claims 16 to 19, characterized in that before and / or after changing the tool with the drive device, a tool feed is performed during chip removal, preferably parallel to the adjustment movement and / or synchronized with a workpiece rotation.