Workpiece bearing unit, machine tool and method for clamping a workpiece

Abstract

The machine tool (10) according to the invention has a work spindle (20), a workpiece table (12) and a workpiece holding device (15), which is attachable to the workpiece table (12), for supporting workpieces (11) that are long and / or have a complex shape, wherein the workpiece holding device (15) has an interchangeable workpiece bearing unit (21) which can be used to hold or support the workpiece (11) at a particular point. The particular feature of the present invention is that the workpiece bearing unit (21) can be interchanged automatically by the work spindle (20).

Description

Gebr. Heller Maschinenfabrik 3. Januar 2024 GmbH HELM P086 WO Gebrüder-Heller-Straße 15Keyword: Aus-72622 NürtingenReplaceable tailstock centerWorkpiece storage unit, machine tool and method for clamping a workpiece

[0001] The invention relates to workpiece storage units, machine tools which are particularly designed for machining workpieces, and methods for clamping workpieces in such machine tools.

[0002] In machine tools, such as those designed as numerically controlled (CNC) machining centers, workpieces of various shapes can be machined. Such machine tools typically have a workpiece table on which the workpieces to be machined can be placed and clamped either directly or using workpiece carrier pallets.

[0003] Particularly in the case of elongated and / or complex-shaped and / or particularly thin-walled workpieces, such as turbine blades or shift drums, it may be necessary to support the workpieces at least during certain machining steps at least at one additional point in order to avoid inaccurate machining results and / or damage to the workpieces, the tools or even the machining center due to vibrations and / or oscillations of the workpieces.

[0004] DE 10 2009 059 659 B4 describes a machine tool with a rotary table, which has a support plate connected to the The workpiece holding device is movable around the turntable, rotatable concentrically to the turntable, and, if necessary, can be locked in a rotationally fixed manner relative to the machine frame. This workpiece holding device has a support frame that is mounted on the turntable or on the workpiece carrier pallet by means of a pivot bearing so that it can rotate about the turntable axis.

[0005] DE 10 2008 013 716 B4 discloses a machine tool for machining a workpiece with a central bore. The workpiece has a central bore that is mounted on a mandrel of a workpiece support. The workpiece is held between the workpiece support and a counterholder with contact pressure.

[0006] FR 2860448 describes a machine tool with a frame and a movable carriage provided with a workpiece carrier. The workpiece carrier is rotated about a first axis by first drive means. It also describes a device with a holder configured to hold the position of the workpiece to be machined. For this purpose, the device has a center whose height above the workpiece carrier is adjustable.

[0007] Furthermore, JP 2015-112680 A describes a machine tool in which the end of the elongated workpiece remote from the workpiece table is held by a device having a tip for supporting the remote end. The rotating member disposed at the remote end has a tip and a support ring that can be selectively used to support the elongated workpiece.

[0008] Based on this, it is the object of the invention to provide an improved machine tool with a workpiece holding device which can be adapted in particular flexibly and automatically to different, elongated and / or complex-shaped workpieces.

[0009] This object is achieved with the workpiece storage unit for supporting a workpiece according to claim 1, the machine tool according to claim 13 and the method according to claim 17:

[0010] The workpiece storage unit according to the invention for supporting a workpiece at a support point in a machine tool has a base body, a first coupling interface comprising a coupling mechanism accommodated in the base body, and a second coupling interface configured to be detachably coupled to a transfer device, wherein the coupling mechanism of the first coupling interface is configured to be actuated by means of the transfer device. The work spindle of a machine tool preferably serves as the transfer device. A tool changer, an end effector, for example of a robot arm, or the like can also serve as the transfer device. A coupling interface is preferably an interface at which the workpiece storage unit can be connected to another device, for example with a workpiece holding device of the machine tool or a transfer device, such asthe work spindle. For example, the second coupling interface can be designed as a hollow shaft cone, whereby the workpiece storage unit can be detachably coupled to the work spindle of the machine tool.

[0011] This makes it possible to replace the workpiece storage unit automatically, i.e., without manual intervention. This can shorten the changeover time of the machine tool and also increase flexibility, as the workpiece storage unit can be adapted to the workpiece by exchanging it. For example, different workpiece storage units can be provided, for example in a tool magazine, inserted into the storage holder via the work spindle, and then removably coupled to the workpiece storage device.

[0012] The first coupling interface and the second coupling interface can be arranged on a longitudinal axis of the base body of the workpiece storage unit, thereby simplifying the design of the coupling mechanism of the first coupling interface, which can be actuated via the second coupling interface. Furthermore, the first coupling interface and the second coupling interface can be arranged at a predetermined angle to each other.

[0013] The machine tool according to the invention comprises a work spindle, a workpiece table, a drive device, and a workpiece holding device. The work spindle is driven to rotate about a spindle axis and has a tool holder for receiving tool holders. The workpiece table is designed to receive a workpiece. The workpiece can be clamped either directly or indirectly on the workpiece table via a workpiece carrier pallet. The workpiece table is displaceable and / or rotatable relative to the work spindle. The drive device is designed to generate defined relative movements between the work spindle and the workpiece table. The workpiece holding device is attached to the Attached or at least attachable to the workpiece table and serves to additionally apply a tensile force and / or compressive force to the workpiece at a support point. For example, this support point can be arranged at a location on the workpiece remote from the workpiece table or the workpiece carrier pallet. Supporting the workpiece comprises, in particular, supporting the workpiece or tensile clamping of the workpiece at the support point. For supporting (applying a compressive force) or for tensile clamping (applying a tensile force) of the workpiece, the workpiece holding device can have at least one workpiece storage unit of the above type, which is in mechanical contact with the workpiece. At the location of the workpiece, the workpiece holding device has a bearing receptacle designed to receive a workpiece storage unit.To store the workpiece, the workpiece storage unit can have a contact element which, for example, has a defined bearing surface that comes into mechanical contact with the workpiece.

[0014] Furthermore, this allows the workpiece storage unit to be removed from the bearing holder to enable machining of the workpiece in the area of the additional support point, whereby access to this area with the work spindle is otherwise blocked by the workpiece storage unit.

[0015] A special feature of the workpiece storage unit and the machine tool according to the invention is that the coupling and decoupling of the workpiece storage unit with the bearing receptacle of the workpiece holding device can be actuated with the work spindle as a transfer device. This is possible, in particular, without the need for additional media, such as fluids such as compressed air or hydraulic fluids, or electrical power supplies, to be provided in the work spindle and / or in the workpiece holding device for actuating the coupling and decoupling in the workpiece holding device. The locking mechanism or coupling mechanism between the workpiece storage unit and the workpiece holding device can be preloaded into a locking position, so that it is designed to be intrinsically safe.As a result, the workpiece storage unit inserted into the bearing holder can remain coupled to the workpiece holding device even in the event of a media supply failure. The tool storage unit is particularly designed such that it can absorb tensile forces and / or compressive forces when coupled to the workpiece holding device in the bearing holder. By applying tensile forces to the workpiece, the tendency of the workpiece to vibrate during machining can advantageously be reduced. To apply tensile forces to the workpiece, the workpiece storage unit can, for example, have at least one corresponding gripping means with which the workpiece can be gripped and subjected to a tensile force.

[0016] All features and advantages described with respect to the workpiece storage unit according to the invention, in particular with respect to the detachable coupling of the workpiece storage unit to the machine tool, are also applicable to the machine tool according to the invention.

[0017] The second coupling interface of the workpiece storage unit preferably corresponds to a coupling interface of a tool holder, so that the workpiece storage unit can be detachably connected to the The first coupling interface can be coupled to the work spindle. For example, the coupling interface can be designed as a hollow shaft taper. The first coupling interface is designed to be actuated, in particular, by means of the work spindle.

[0018] In a specific embodiment, the workpiece holding device can be a tailstock. The workpiece holding device can have at least one clamp-shaped clamping frame that spans the workpiece, or at least one separate workpiece support unit that is connected to the workpiece table or the workpiece carrier pallet at the point on the workpiece to be supported. The bearing receptacle for the workpiece storage unit is arranged at the other end of the clamp-shaped workpiece holding device. The workpiece storage unit can, for example, be at least substantially cylindrical, wherein the base area of the cylinder can be elliptical, circular, rectangular, square, or polygonal. The bearing receptacle can accordingly be designed as a bore in the workpiece holding device, the inner contour of which can be adapted to the outer contour of the workpiece storage unit.The inner diameter of the bore can be adapted to the outer diameter of the workpiece storage unit. For example, the circumference of the workpiece storage unit forms a contact surface between the workpiece storage unit and the bearing holder. At an end of the workpiece storage unit facing the workpiece, the latter can have a workpiece contact element, for example a centering point. A surface facing the workpiece can form the workpiece storage surface of the workpiece storage unit, which can be designed, for example, conical or frustoconical. The workpiece storage device can, however, also have a The workpiece support unit can have a shape that differs from the conical tip shape. For example, the end facing the workpiece can be designed as a fitting piece that fits into an existing opening in the workpiece. The workpiece support unit can also carry gripping or clamping devices, e.g., a jaw chuck or other device with clamping elements. The clamping elements can be connected to one or more actuators.

[0019] In particular, the base body of the workpiece storage unit defines a longitudinal axis. The coupling mechanism housed in the base body is particularly designed to lock or release the workpiece storage unit in the bearing receptacle. The base body of the workpiece storage unit can be at least substantially cylindrical, wherein the base surface of the base body can be elliptical, circular, rectangular, square, or polygonal. It is preferred that the base surface of the base body be circular. The base body defines, in particular, a longitudinal axis.

[0020] Preferably, the coupling mechanism comprises a slider which is displaceable relative to the base body along a longitudinal axis of the base body.

[0021] The first coupling interface has, in particular, at least one locking element, preferably a plurality of locking elements, which is / are displaceable transversely to the longitudinal axis of the base body by means of the slider. The at least one locking element is preferably displaceable by means of the slider such that the at least one locking element protrudes from a base body circumferential surface. Furthermore, the at least one locking element can preferably be brought into engagement with a recess in the bearing receptacle when the workpiece storage unit is inserted into the bearing receptacle of the workpiece holding device. Displacement of the slider thus leads to the coupling and decoupling of the workpiece storage unit with the workpiece holding device. The at least one locking element can be designed as a rolling element element, which is / are held in at least one locking element bore or at least one locking element groove in the base body.The at least one rolling element can be formed, for example, as ball elements, as cylindrical roller elements, as needle elements, or as tapered roller elements, wherein the bearing mount can be adapted to the workpiece bearing unit in such a way that the locking elements of the workpiece bearing unit, together with the bearing mount, form a rolling bearing (around the longitudinal axis of the base body). The locking elements thus serve, on the one hand, to lock the workpiece bearing unit in the bearing mount and, on the other hand, to rotatably support the workpiece bearing unit in the bearing mount. For example, the at least one locking element bore or the at least one locking element groove can be shaped in such a way that the at least one locking element bore or the at least one locking element groove tapers (radially) outwards.The at least one locking element is thus held in the at least one locking element bore or the at least one locking element groove when the at least one locking element protrudes from the base body circumferential surface. The at least one locking element can also be guided and held in a cage within the at least one locking element bore or the at least one locking element groove when the at least one locking element protrudes from the base body circumferential surface.

[0022] In particular, the work spindle of the machine tool is used as a transfer device for the Workpiece storage unit. The tool holder of the work spindle has, in particular, a collet chuck and a push-pull element. The push-pull element is preferably driven so as to be displaceable along the longitudinal axis.

[0023] It is preferred that the slider of the coupling mechanism be displaceable along the longitudinal axis of the base body by means of the push-pull element of the work spindle, whereby the coupling mechanism can be actuated by displacing the slider. This enables actuation of the coupling mechanism by means of the push-pull element of the work spindle.

[0024] The workpiece storage unit preferably has a spring element that applies a spring force to the slide. In particular, the slide is preloaded by the spring element into a first locking position, in which the at least one locking element is held protruding from the peripheral surface of the base body. By preloading the slide toward the first locking position, the workpiece storage unit remains coupled to the workpiece holding device, even if the slide of the coupling mechanism is not in contact with the tension-compression element or is not moved by it.

[0025] In particular, the slide can be brought into a release position, for example by means of the tension-compression element of the work spindle, against a spring force acting on the slide by the spring element, in which the at least one locking element is held so as not to protrude from the peripheral surface of the base body. In the release position, the workpiece storage unit can be moved out of and into the bearing receptacle of the workpiece holding device.

[0026] In particular, the slide can be brought into a second locking position, for example by means of the tension-compression element of the work spindle, against the spring force acting on the slide by the spring element, in which the at least one locking element is (likewise) held protruding from the base body circumferential surface.

[0027] In particular, the release position is arranged between the first and second locking positions. The first and second locking positions preferably form the end positions of the slide.

[0028] The workpiece storage unit is moved into the release position by means of the tension-compression element, particularly when the workpiece storage unit is inserted into the bearing receptacle of the workpiece holding device. To decouple the work spindle from the coupling interface of the workpiece storage unit, the tension-compression element of the work spindle is moved toward the side of the workpiece storage unit facing the workpiece in order to release the collet of the work spindle. With the movement of the tension-compression element toward the side of the workpiece storage unit facing the workpiece, the slide of the coupling mechanism in the workpiece storage unit is moved into the second locking position. If the tension-compression element is now removed from the coupling interface together with the collet, the spring element guides the slide toward the side of the workpiece storage unit facing the work spindle, so that the slide is moved into the first locking position.

[0029] In particular, the slide has a flushing fluid channel, which preferably runs at least substantially along the longitudinal axis of the workpiece storage unit and can be supplied with a flushing fluid, e.g., via the work spindle. The flushing fluid channel can thus transport flushing fluid to a flushing fluid opening. The flushing fluid can be liquid or gaseous. For example, compressed air (e.g., in dry machining) or a flushing fluid, such as lubricating or cutting oil, can be used as the flushing fluid.

[0030] The base body of the workpiece storage unit preferably contains at least one flushing fluid bore, which can be supplied with flushing fluid via the flushing fluid channel and through which the flushing fluid can be sprayed. In particular, the base body of the workpiece storage unit contains at least one flushing fluid bore through which the flushing fluid can be sprayed. The at least one flushing fluid bore can be arranged further toward the side of the workpiece storage unit facing the workpiece than the at least one locking element. This makes it possible to clean the bearing mount with flushing fluid when inserting the workpiece storage unit, before the base body peripheral surface of the workpiece storage unit is seated in the bearing mount.This allows any contaminants, such as chips, deposits, and the like, that have accumulated in the bearing support can be removed. If left unchecked, these can lead to inaccuracies in the placement and alignment of the workpiece storage unit. Such inaccuracies can result in less accurate machining results.

[0031] Preferably, the machine tool also has a tool magazine that is designed to accommodate and provide a plurality of tool holders, in particular with different tools, as well as at least one workpiece storage unit. This makes it It is possible to accommodate at least one workpiece storage unit, but preferably several (different) workpiece storage units, in the tool magazine and to make them available there for inclusion in the work spindle.

[0032] The method according to the invention for clamping a workpiece in a machine tool of the above type comprises the following:

[0033] Coupling the workpiece storage unit of the above type with the transfer device, preferably with the work spindle serving as the transfer device;

[0034] Inserting the workpiece storage unit into the bearing holder of the workpiece holding device; and

[0035] Coupling the workpiece storage unit to the workpiece holding device; and preferably decoupling the transfer device, preferably the work spindle serving as the transfer device, from the workpiece storage unit.

[0036] All features and advantages described with respect to the workpiece storage unit according to the invention and / or the machine tool according to the invention are also applicable to the method according to the invention.

[0037] Preferably, the coupling mechanism for coupling the workpiece storage unit to the workpiece holding device is actuated by means of the work spindle.

[0038] Further details of advantageous developments or details of the invention can be found in the drawings of the description and in the dependent claims. They show:

[0039] Figure 1 is a schematic view of an embodiment of the machine tool according to the invention;

[0040] Figure 2 shows an embodiment of the workpiece storage unit in the uncoupled state;

[0041] Figures 3 and 4 show the embodiment of the workpiece storage unit during coupling with the work spindle;

[0042] Figures 5 to 8 show the embodiment of the workpiece storage unit from Figures 2-4 during coupling with the workpiece holding device and during decoupling of the workpiece storage unit from the work spindle.

[0043] Figure 1 shows a schematic view of an embodiment of the machine tool 10 according to the invention. In Figure 1, one type of machine tool is shown, although the machine tool can represent any type of machine tool 10 on which the concept according to the invention with work spindle, workpiece table or workpiece carrier pallet and workpiece holding device, as well as with exchangeable workpiece storage unit, can be implemented.

[0044] The machine tool 10 is preferably a machine tool intended for machining, for example in the form of the machining center illustrated in Figure 1. The machining center as machine tool 10 includes a machine frame 13 on which a spindle tower 19 with a work spindle 20 with multiple drives is arranged, which can be moved in at least one, preferably several, directions.

[0045] In the present embodiment, the work spindle 20 is movable vertically (along a Y-axis) and horizontally (along an X-axis). Furthermore, the work spindle 20 is driven to rotate about a spindle axis D by means of a drive device not further illustrated. In the example shown in Figure 1, the spindle axis D runs parallel to a Z-axis.

[0046] Tool holders 24 and workpiece storage units 21 can be connected (coupled) to the work spindle 20 as needed. These can be kept ready in a tool magazine 22. By means of a tool changing device 23, the tool holders 24 or the workpiece storage units 21 can be transferred from the work spindle 20 to the tool magazine 22 and from the tool magazine 22 to the work spindle 20. Figure 1 shows a workpiece storage unit 21 coupled to the work spindle 20.

[0047] The machine tool 10 has a workpiece table 12 on which the workpiece 11 to be machined can be clamped. The workpiece 11 to be machined is preferably a complexly shaped and / or long workpiece 11, for which it is advantageous to support the workpiece 11 at least for certain machining steps at at least one further end of the workpiece 11, i.e., to clamp the workpiece 11 preferably between at least two workpiece clamping points.

[0048] In Figure 1, the workpiece table 12 has, for example, a rotary table 14 that is driven and movable along a vertically oriented B-axis and along a horizontally oriented A-axis. The workpiece holding device 15 is mounted on the rotary table 14. The workpiece holding device 15 can be mounted directly on the workpiece table 12 or indirectly via a workpiece carrier pallet 14.

[0049] The workpiece table 12 is movable along the Z-axis. The workpiece table 12 in Figure 1 is also configured to rotate about an A-axis transverse to the Z-axis. Furthermore, the workpiece table 12 is configured to rotate about a B-axis transverse to the A- and Z-axes.

[0050] In the example shown in Figure 1, the workpiece holding device 15 has a workpiece clamping unit 16 configured to clamp the workpiece 11 at a first end. A workpiece support unit 17 of the workpiece holding device 15 is arranged at the second, free end of the workpiece 11. In Figure 1, the workpiece support unit 17 is arranged at a fixed distance from the workpiece clamping unit 16.

[0051] In the embodiment shown in Figure 1, the workpiece 11 is suspended or clamped in the clamped state between the workpiece clamping unit 16 and the workpiece storage unit 21. It is also conceivable for the workpiece support unit 17 to be mechanically connected directly to the workpiece clamping unit 16 or to be connected via the workpiece table 12 instead of the rotary table 14. In such an embodiment (not shown), the workpiece holding device 15 has a clamping frame. The workpiece support unit 17 has a bearing holder 18 designed to accommodate a workpiece storage unit 21.

[0052] The machine tool 10 shown in Figure 1 allows the workpiece storage unit 21 of the workpiece holding device 15 to be exchanged with the work spindle 20 and stored in the tool magazine 22. This allows the workpiece storage unit 21 to be automatically mounted on the workpiece table 12 with the machine tool 10, matching the workpiece 11.

[0053] Figure 2 shows an embodiment of a workpiece storage unit 21. The workpiece storage unit 21 has a base body 27 that extends along a longitudinal axis L from an end 25 facing the work spindle 20 to an end 26 facing the workpiece 11. The base body 27 can be at least substantially cylindrical. The workpiece storage unit 21 has a first coupling interface KS1. The first coupling interface KS1 comprises a plurality of locking elements 32, a base body circumferential surface 33, a stop ring 48, and a coupling mechanism housed in the base body 27. At the end 25 of the base body 27 facing the work spindle 20, the workpiece storage unit 21 has a second coupling interface KS2, at which the work spindle 20 can be releasably coupled to the workpiece storage unit 21. The second coupling interface KS2 shown in Figure 2 is designed as a hollow shaft cone.Other embodiments of this coupling interface are also possible. In the example shown in Figures 2-8, the first coupling interface KS1 and the second coupling interface KS2 are arranged on the longitudinal axis L of the workpiece storage unit 21. In other embodiments, the first coupling interface KS1 and the second coupling interface KS2 can be arranged at a predetermined angle to one another, for example in the range of 60° to 120°, preferably in the range of 70° to 110°, in particular in the range of 80° to 100°, particularly preferably approximately 90°.

[0054] At the end 26 of the base body 27 facing the workpiece 11, the workpiece storage unit 21 has a bearing element 43, which in the example shown in Figure 2 is designed as a tip. Unlike what is shown in Figure 2, the bearing element 43 can also be designed as a bearing ring with a recess, a fitting piece for a recess in the workpiece 11, a clamping element, a ring element, or the like. Alternatively, instead of a bearing element 43, a gripping or clamping means can also be provided at the end 26 of the base body facing the workpiece 11 in order to apply a tensile force to the workpiece 11.

[0055] A slide 28 is housed in the base body 27 of the workpiece storage unit 21. The slide 28 is slidably mounted along the longitudinal axis L between a first locking position SP1 and a second locking position SP2. The first locking position SP1 is defined by an annular shoulder 29 within the base body 27, which forms a stop surface for the slide head 30 of the slide 28. The workpiece storage unit 21 also has a spring element 31 arranged within the base body 27 such that the spring element 31 exerts a force on the slide 28 in the direction of the end 25 facing the work spindle 20. The slide 28 is thus preloaded in the direction of the first locking position SP1.

[0056] The slide head 30 is at least substantially cylindrical and has a circumferential contour UK, the distance from the longitudinal axis L of which varies depending on the axial position.

[0057] The workpiece storage unit 21 also has at least one locking element 32 which, depending on the longitudinal position of the slide 28 protrudes or does not protrude from the base body circumferential surface 33 transversely to the longitudinal axis L. The locking elements 32 serve to lock the workpiece storage unit 21 in the bearing receptacle 18. Figure 2 shows the plurality of locking elements arranged along the circumference of the base body 27. In the embodiment shown in Figure 2, the locking elements 32 are spherical, so that the locking elements 32 serve a dual function, namely to lock the workpiece storage unit 21 in the bearing receptacle 18 and also to rotatably support the workpiece storage unit 21 in the bearing receptacle 18. It is also possible for the locking elements 32 to be designed differently, for example, pin-shaped. The locking elements 32 are arranged in an outwardly tapered groove, which is dimensioned such that the locking elements 32 are held in the groove. The locking elements 32 cannot fall out of the groove.Alternatively, a cage can be arranged in the groove, by means of which the locking elements 32 are held in the groove.

[0058] At the end 25 of the base body 27 facing the work spindle 20, the slide 28 has an actuating section 34 against which the spring element 31 rests. On the side of the actuating section facing the work spindle, the latter has an actuating surface. The coupling mechanism can be actuated by pressing against the actuating surface with a force that is greater than the spring force of the spring element 31, so that the slide 28 can be moved from the first locking position SP1 to the release position F and further into the second locking position SP2.

[0059] In the example shown, the work spindle 20 is designed to actuate the coupling mechanism with the work spindle 20. The work spindle 20 has a collet 35 and a tension-compression element.

[0060] The pull-push element 36 can be moved relative to the collet 35 in the Z direction by a drive (not shown). The pull-push element 36 is configured to actuate the slide 28 by being pressed against the actuating surface of the actuating portion 34 of the slide 28.

[0061] In addition, the tension-compression element 36 is configured to couple the collet 35 to the second coupling interface KS2 at the end 25 of the workpiece storage unit 21 facing the work spindle 20. For this purpose, the tension-compression element 36 has an outer cone 39. The collet 35 has a corresponding inner cone 38, wherein the inclination of the outer cone 39 of the tension-compression element 36 is adapted to the inclination of the inner cone 38 of the collet 35. The collet 35 also has an outer cone 37. The inclination of the outer cone 37 of the collet 35 is adapted to the inclination of an inner cone 40 provided in the second coupling interface KS2 at the end 25 of the workpiece storage unit 21 facing the work spindle 20. The pull-push element 36 serves to actuate the slide 28 and (simultaneously) to clamp the collet 35 to the workpiece storage unit 21.

[0062] In addition, the slide 28 has a flushing fluid channel 41 which extends within the slide 28. Preferably, the flushing fluid channel 41 extends along the longitudinal axis L. The flushing fluid channel 41 is arranged above a fluid channel formed in the tension-compression element 36 49 of the work spindle 20 can be supplied with a flushing fluid. The flushing fluid channel 41 can branch into further fluid channels 50, through which flushing fluid can also be guided into the bearing element 43. Inclined fluid channel sections 51 can be accommodated in the bearing element 43, through which the flushing fluid can be sprayed at an angle relative to the longitudinal axis L. In the example shown in Figures 2-8, the bearing element 43 is additionally designed for cleaning the bearing receptacle 18, as shown in particular in Figure 5, which ensures that the bearing receptacle 18 can be cleaned, i.e., freed from any contaminants. In a particularly preferred embodiment, the bearing element 43 is designed to be rotatable (about the longitudinal axis L) relative to the base body 27.In this embodiment, the inclined fluid channel sections 51 are arranged such that the escape of flushing fluid from the bearing element 43, due to the recoil, creates a torque on the bearing element 43, which causes the bearing element 43 to rotate. The cleaning effect can be further improved by the bearing element rotating during spraying, which acts like a rotating spray nozzle for the flushing fluid. In this embodiment, in which the bearing element 43 is rotatably mounted, the workpiece storage unit 21 has a rotary distributor 52 between the additional fluid channels 50 and the fluid channel sections 51 in the bearing element 43. The rotary distributor 52 serves to seal the flushing fluid connection, thereby preventing flushing fluid from accidentally escaping within the workpiece storage unit 21. The flushing fluid channel 41 ends in at least one, preferably in several flushing fluid bores 42 in the base body 27.The flushing fluid bores 42 can run transversely to the longitudinal axis L (i.e. radially), so that flushing fluid is transverse to the longitudinal axis. L is sprayable. The flushing fluid bore 42 exits from the base body 27 below the blocking elements 32 and / or between the blocking elements 32. In the exemplary embodiment shown in Figure 2, the slide 28 in the slide head 30 has a flushing fluid channel section 45 which runs transversely to the longitudinal axis L. Flushing fluid can only be sprayed when the transversely running flushing fluid channel section 45 in the slide head 30 is aligned with the flushing fluid bore 42 in the base body 27, which is shown in Figures 4 and 7, namely when the slide 28 is brought into the release position.

[0063] The machine tool 10 described so far operates with reference to Figures 2-8 as described below, whereby the above description applies accordingly to Figures 2-8 with reference to the reference numerals:

[0064] The workpiece storage unit 21 shown in Figure 2 can, for example, be located in the tool changing device 23 of the tool magazine 22 (not shown here).

[0065] Figures 2-4 describe how the workpiece storage unit 21 is coupled to the work spindle 20. The tension-compression element 36 and the collet 35 of the work spindle 20 are inserted in Figure 3 into the second coupling interface KS2 at the end 25 of the workpiece storage unit 21 facing the work spindle 20. The surface of the outer cone 37 of the collet 35 rests against the surface of the inner cone 40 of the workpiece storage unit 21. The collet 35 is preloaded into this position by a circumferential spring element 44. The tension-compression element 36 pushes the slide 28 against the force exerted by the spring element 31 on the Slider 28 acting spring force into the second locking position lung SP2.

[0066] Figure 4 illustrates how the collet 35 is clamped in the second coupling interface KS2 of the workpiece storage unit 21 by means of the tension-compression element 36. For this purpose, the tension-compression element 36 is displaced relative to the collet 35 so that the surface of the outer cone 39 of the tension-compression element 36 rests against the surface of the inner cone 38 of the collet 35 and pushes the collet outward. At the same time, the spring force of the spring element 31 of the slide 28 continues to act in the direction of the end 25 of the workpiece storage unit 21 facing the work spindle 20, so that the slide 28 is displaced in this direction along the longitudinal axis L. In Figure 4, the slide 28 is now in the release position F. In the release position F, the transverse flushing fluid channel section 45 is aligned with the flushing fluid opening 42. In the release position F, the blocking elements 32 are located in a recess 46 in the circumferential contour UK of the slide 28.In this release position F, the locking elements 32 do not protrude from the base body peripheral surface 33.

[0067] In Figure 5, the workpiece storage unit 21 is now inserted into the bearing receptacle 18 of the workpiece holding device 15 or the workpiece support unit 17 by means of the work spindle 20. During the insertion of the workpiece storage unit 21 into the bearing receptacle 18, flushing fluid can be sprayed via the flushing fluid bore 42 so that the bearing receptacle 18 can be cleaned of contaminants during the insertion of the workpiece storage unit 21. The bearing receptacle 18 has a bearing recess 47, designed as an annular groove in Figure 5, which is adapted such that the locking elements 32 of the workpiece storage unit 21 can be be received when the slide 28 has been brought into the first locking position SP1 or the second locking position SP2, so that the workpiece storage unit 21 is locked or arrested in the bearing holder 18.

[0068] In Figure 6, the workpiece storage unit 21 is arranged completely in the bearing receptacle 18. On the outer circumference, the workpiece storage unit 21 has a stop ring 48, which bears against the workpiece holding device 15 when the workpiece storage unit 21 is fully inserted into the bearing receptacle 18.

[0069] The work spindle 20 is decoupled from the workpiece storage unit 21 by displacing the tension-compression element 36 toward the workpiece storage unit 21. The slide 28 is thus moved into the second locking position SP2 by the tension-compression element 36, whereby the locking elements 32 are pushed radially outward into the bearing recess 47 by the slide. The workpiece storage unit 21 is thus at least temporarily locked in the bearing holder 18.

[0070] Figure 7 shows the previously described embodiment while the collet 35 and the tension-compression element 36 are removed from the second coupling interface KS2 of the workpiece storage unit 21. In Figure 7, the slide 28 is briefly in the release position F. However, in this situation, the spring element 31 continues to press against the slide 28, so that the workpiece storage unit 21 remains held in the bearing receptacle 18 by the spring element 31. In this position, the slide 28 is not yet in its end position (the first locking position SP1).

[0071] In Figure 8, the work spindle is now removed from the second coupling interface KS2 of the workpiece storage unit 21, with the spring element 31 having moved the slide 28 into the first locking position SP1. In this position, the locking elements 32 clamp the workpiece storage unit 21 to the workpiece holding device 15. The surfaces on the outer circumference of the slide 28 that interact with the locking elements 32 are designed to be self-locking. This means that even high forces acting on the locking elements 32 cannot move the slide 28 from its position.

[0072] The machine tool 10 according to the invention comprises a work spindle 20, a workpiece table 12, and a workpiece holding device 15 attachable to the workpiece table 12 for supporting long and / or complexly shaped workpieces 11. The workpiece holding device 15 comprises an exchangeable workpiece storage unit 21 with which the workpiece 11 can be held or stored in one location. The special feature of the present invention is that the workpiece storage unit 21 can be exchanged automatically by means of the work spindle 20. Reference symbols: 10 Machine tool 11 Workpiece 12 Workpiece table 13 Machine frame 14 Workpiece pallet 15 Workpiece holding device 16 Workpiece clamping unit 17 Workpiece support unit 18 Bearing mount 19 Tool holder mount 20 Work spindle 21 Workpiece storage unit 22 Tool magazine 23 Tool changing device 24 Tool holder 25 End facing the work spindle 26 End facing the workpiece 27 Base body 28 Slide 29 Annular shoulder 30 Slide head 31 Spring element 32 Locking elements 33 Base body peripheral surface 34 Actuating section 35 Collet 36 Tension-compression element 37 Outer cone of the collet 38 Inner cone of the collet 39 Outer cone of the tension-compression element 40 Inner cone of the coupling interface 41 Flushing fluid channel 42 Flushing fluid bore 43 Bearing element 44 Circumferential spring element 45 Flushing fluid channel section 46 Recess 47 Bearing recess 48 Stop ring 49 Fluid channel 50 Additional fluid channels 51 Fluid channel sections 52 Rotary distributor A A-Achse AS support point B B-AchseF Release position KS1 first coupling interface KS2 second coupling interface L Longitudinal axis SP1 first locking position SP2 second locking position UK Circumferential contour X X-Achse Y Y-Achse Z Z-Achse

Claims

Patent claims:

1. Werkstücklagereinheit (21) zum Stützen eines Werk- piece (11) at a support point (AS) in a tool z eugmaschine (10), mit einem Grundkörper (27), einer ersten Koppelschnittstelle (KS1), die einen in dem base body (27) accommodated coupling actuation mechanism, and a second coupling section telle (KS2), die dazu eingerichtet ist, mit einer Übergabeeinrichtung lösbar gekoppelt zu werden, wobei the coupling actuation mechanism of the first coupling interface (KS1) is designed to be actuated by means of the transfer device.

2. Werkstücklagereinheit (21) nach Anspruch 1, dadurch characterized in that the second coupling interface (KS2) is designed to be connected to a work spindle (20) of the machine tool (10) as a transfer device ung lösbar gekoppelt zu werden, wobei die erste Kop- pelschnittstelle (KS1) mittels der Arbeitsspindel (20) is designed to be operable.

3. Werkstücklagereinheit (21) nach Anspruch 1 oder 2, characterized in that the coupling mechanism has a slider (28) which is displaceable along a longitudinal axis (L) of the base body (27) relative to the base body (27).

4. Werkstücklagereinheit (21) nach Anspruch 3, dadurch characterized in that the first coupling interface ( KS1) mindestens ein Sperrelement (32) aufweist, das can be moved transversely to the longitudinal axis (L) of the base body (27) by means of the slider (28).

5. Werkstücklagereinheit (21) nach Anspruch 4, dadurchcharacterized in that the at least one locking element (32) is displaceable by means of the slider (28) such that it protrudes from a base body peripheral surface (33).

6. Werkstücklagereinheit (21) nach Anspruch 4 oder 5, characterized in that the at least one locking element (32) is designed as a rolling element.

7. Werkstücklagereinheit (21) nach einem der Ansprüche 4 to 6, characterized in that the slide (28) m ittels eines Federelements (31) in eine erste Sperr- stellung (SP1) vorgespannt ist, in der das mindestens a locking element (32) is held protruding from the base body peripheral surface (33).

8. Werkstücklagereinheit (21) nach Anspruch 7, dadurch characterized in that the slide (28) is counter to a d urch das Federelement (31) auf den Schieber (28) wirkende Federkraft in eine Freigabestellung (F) can be brought in which the at least one locking element (32) is not held protruding from the base body peripheral surface (33).

9. Werkstücklagereinheit (21) nach Anspruch 7 oder 8, characterized in that the slider (28) is en der durch das Federelement (31) auf den Schieber (28) acting spring force can be brought into a second locking position (SP2), in which the at least one locking element (32) is separated from the base body circumferential surface (33) is held above.

10. Werkstücklagereinheit (21) nach einem der Ansprüche 7to 9, characterized in that the release position l ung (F) zwischen der ersten und der zweiten Sperr- stellung (SP1, SP2) angeordnet ist.

11. Werkstücklagereinheit (21) nach einem der vorherge- claims, characterized in that the slide (28) has a flushing fluid channel (41) which preferably runs at least substantially along the longitudinal axis (L) and can be supplied with a flushing fluid.

12. Werkstücklagereinheit (21) nach einem der vorherge- claims, characterized in that the base body (27) of the workpiece storage unit (21) has at least one flushing fluid bore (42) which can be supplied with flushing fluid via the flushing fluid channel (41) and through which the flushing fluid can be sprayed.

13. Werkzeugmaschine (10), die insbesondere zur spanenden Bearbeitung von Werkstücken (11) eingerichtet ist, comprising: - eine um eine Spindelachse (D) drehend angetriebene Work spindle (20) with a tool holder receptacle (19) for receiving tool holders (24); - einen Werkstücktisch (12) zur Aufnahme eines Werk- piece (11), wherein the workpiece table (12) is displaceable and / or rotatable relative to the work spindle (20); - eine Antriebseinrichtung, die dazu eingerichtet is a defined relative movement between Work spindle (20) and workpiece table (12) to be produced; - eine an dem Werkstücktisch (12) angebrachte oderanbringbare Werkstückhaltevorrichtung (15) zur Stüt- tion of the workpiece (11) on at least one additional l ichen Stützstelle (AS) des Werkstücks (11), wobei die Werkstückhaltevorrichtung (15) an dieser Stütz- stelle (AS) eine zur Aufnahme einer Werkstückla- ger unit (21) has a bearing receptacle (18) arranged according to one of the preceding claims.

14. Werkzeugmaschine (10) nach Anspruch 13, dadurch ge- characterized in that the at least one locking element (32) can be brought into engagement with a recess (47) in the bearing receptacle (18) when the workpiece storage unit (21) is in the bearing receptacle (18) of the work- tückhaltevorrichtung (15) angeordnet ist.

15. Werkzeugmaschine (10) nach einem der vorhergehenden Claims, characterized in that the working spindle (20) of the machine tool (10) serves as a transfer e inrichtung für die Werkstücklagereinheit (21) ausge- is formed, wherein the tool holder receptacle (19) of the A rbeitsspindel (20) eine Spannzange (35) und ein Zug- Druck-Element (36) aufweist.

16. Werkzeugmaschine (10) nach einem der vorhergehenden Claims, characterized in that the slider (28) of the coupling mechanism is arranged along the longitudinal axis ( L) des Grundkörpers (27) mittels des Zug-Druck-Ele- mentes (36) der Arbeitsspindel (20) verschiebbar ist, wherein the coupling mechanism can be actuated by moving the slider (28).

17. Werkzeugmaschine (10) nach einem der vorhergehendenClaims, characterized by a tool magazine (22) which is designed to accommodate and provide tool holders (24) and at least one workpiece storage unit (21).

18. Verfahren zum Spannen eines Werkstücks in einer Werk- zeugmaschine (10) nach einem der Ansprüche 13 bis 17, comprehensive: - Koppeln der Werkstücklagereinheit (21) nach einem of claims 1 to 12 with the work spindle (20); - Einführen der Werkstücklagereinheit (21) in die La- geraufnahme (18) der Werkstückhaltevorrichtung (15); as well as - Koppeln der Werkstücklagereinheit (21) mit der Werkstückhaltevorrichtung (15) und Entkoppeln der Workpiece bearing unit (21) from the work spindle (20).

19. Verfahren nach Anspruch 18, dadurch gekennzeichnet, that the coupling mechanism for coupling the workpiece storage unit (21) to the workpiece holding device (15) can be actuated by means of the work spindle (20).

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