Method for operating an arrangement with a machine tool and a tool changer, and a corresponding arrangement

Abstract

Method for operating an arrangement with a machine tool (2) and a tool changer (3), wherein the tool changer (3) has a number of receptacles (4) in which tools (5) can be inserted by means of a spindle (2a) of the machine tool (2) or tools (5) can be removed from the receptacles (4), characterized in that adapters (9) are provided on which workpieces (7) can be fixed, wherein the adapters (9) each have an interface for connection to the spindle (2a), and that adapters (9) with workpieces (7) fixed thereto can be inserted into or removed from the receptacles (4) of the tool changer (3) by means of the spindle (2a).

Description

[0001] The invention relates to a method for operating an arrangement with a machine tool and a tool changer, as well as a corresponding arrangement.

[0002] Such arrangements typically form machining centers, which generally include at least one machine tool. The machine tool has a spindle to which tools can be attached. This allows machining operations, such as milling operations, to be performed on a workpiece positioned at a machining location, for example, a zero-point clamping system.

[0003] To enable the machine tool to perform various machining operations, a tool changer is provided in a known manner. This tool changer acts as a storage unit for multiple tools. For this purpose, the tool changer has a multitude of holders in which the different tools can be stored. The tool changer is advantageously designed as a conveyor system, so that the required tool can be conveyed to a transfer point where the spindle can pick up the tool. The transfer of a tool from the spindle of the machine tool to the tool changer occurs in a similar manner.

[0004] In order to ensure the most fully automated machining processes possible on a machine tool, it is desirable not only to guarantee an automated change of the respective tools for the machine tool, but also to enable an automated change of the workpieces to be machined.

[0005] To enable automated feeding of workpieces to the machining positions, known systems require an additional separate, independent unit, which, for example, includes a robot that can automatically feed workpieces to the respective machining locations.

[0006] A significant disadvantage here is that providing for this separate unit entails considerable costs.

[0007] Another significant problem is that the separate workpiece changing unit is added only after the machine tool with the tool changing device has been commissioned. This means that any CE conformity that was valid for the machine tool with the tool changing device is no longer valid for the entire system. Therefore, CE conformity must be obtained and demonstrated anew for the entire system, which is particularly problematic if the manufacturers of the machine tool and the additional unit are different.

[0008] A tool changing device for a machine tool is known from DE 10 2017 101 737 A1. The tool changing device allows tools to be fed to a changing position, from which each tool can be fed to a tool holder of the machine tool. Furthermore, a transfer unit with coupling means is provided, by means of which workpieces are coupled to the feeding movement of the tools. The workpieces can be fed to the tool changing position or another changing position by means of the transfer unit, from which each workpiece can be fed to a machining position.

[0009] The coupling means are each assigned to a holder for a tool and form a separate receiving space for a workpiece, namely one that is set off from the holder.

[0010] This not only enables automated tool changes, but also automated feeding of workpieces to predetermined machining positions.

[0011] A disadvantage of this system is that the coupling devices require additional installation space, which complicates the handling of the tools and ultimately the workpieces themselves. For example, it is not possible to use double grippers for intermediate handling with such a system.

[0012] DE 199 16 765 A1 relates to a handling tool for a machine tool. To create a handling tool for machine tools that allows for a compact design, a simple and safe gripping and changing process, and insertion into a machining spindle, it is proposed that the gripping elements with gripper carriers, in the radial and / or axial direction, in particular a piston, be movable from the magazine position via a spread, defined intermediate position to a gripping position.

[0013] DE 60 2005 005 042 T2 relates to a workpiece gripping device for machine tools having a motorized chuck attached to a machining head, comprising: a housing, a drive shaft mounted in the housing and provided with a shank that can engage with the chuck, a locking element designed to engage with a counter-engagement element integral with the machining head when the shank engages with the chuck, preventing the rotary movement of the device when the chuck is driven, and at least one gripper having jaws, at least one of which is movable and is operatively coupled to the drive shaft for opening and closing via a gear mechanism.

[0014] The transmission means have an off-center section that is integrally formed with the drive shaft and, in cam cooperation with the movable jaw, counteracts elastic means.

[0015] The JP S61-226241 A refers to a machining center with an automatic tool changing system. Tools are stored in a tool magazine. A movable arm feeds tools from the tool magazine to a spindle. A gripper is also provided for gripping a workpiece. The gripper can remove a workpiece from a storage position on a worktable. The gripper can be inserted into the spindle using a double gripper.

[0016] US 7 103 955 B2 and US 2009 / 0116915 A1 describe machining tools that use double grippers for intermediate tool handling.

[0017] DE 10 2015 103 653 A1 relates to a clamping stock for workpieces, wherein the clamping stock comprises: a base surface on which a machine coupling system is arranged, at least two workpiece clamping jaws which are arranged on the side of the clamping stock opposite the base surface and of which at least one is movably mounted towards and away from the other, a bearing receiving contour which is arranged outside the base surface on a first side of the clamping stock, and a gripper receiving contour which is arranged on a second side of the clamping stock opposite the first side.

[0018] In DD 140 549 A1 and CH 666 440 A5, grippers are described which are adjustable to grip different workpieces.

[0019] The invention is based on the objective of providing a method and an arrangement of the type mentioned above, in which increased functionality is achieved with minimal design effort.

[0020] The problem is solved by a method for operating an arrangement with a machine tool and a tool changer according to the features of claim 1. The problem is further solved by an arrangement according to the features of claim 7.

[0021] Advantageous embodiments and expedient further developments of the invention are described in the dependent claims.

[0022] The invention relates to a method for operating an arrangement with a machine tool and a tool changer. The tool changer has a number of holders into which tools can be inserted or removed by means of a spindle of the machine tool, and comprises adapters to which workpieces can be fixed. The adapters each have an interface for connection to the spindle. By means of the spindle, adapters with workpieces fixed to them can be inserted into or removed from the holders of the tool changer.

[0023] The invention further relates to a corresponding arrangement.

[0024] A significant advantage of the invention is that the adapters according to the invention enable dual use of the tool changer in such a way that not only tools but also workpieces can be stored in its receptacles.

[0025] It is essential that the adapters according to the invention, which receive the workpieces, have the same interface as the tools for connection to the spindle.

[0026] This method takes advantage of the fact that the spindle of the machine tool has a standardized interface in the form of a gripper groove, to which either a tool or an adapter can be attached.

[0027] Not only the tools but also the adapters have the same complementary interface that matches the spindle interface.

[0028] The tool changer allows the spindle to selectively remove either a tool or an adapter, with or without a workpiece, from a tool holder stored in a tool holder. Similarly, the spindle can be used to feed a workpiece or an adapter, with or without a workpiece, from a tool holder.

[0029] The tool changer advantageously forms a conveying system that allows a tool changer holder to be selectively conveyed to a transfer point, where the spindle can pick up a workpiece or adapter stored in this holder, with or without a workpiece. Likewise, a workpiece or adapter can be placed on the spindle and deposited into this holder.

[0030] A key aspect of the invention is that the adapter can be handled completely identically to a tool, with or without a workpiece attached to it.

[0031] Crucially, no design modifications are required to the tool changer to accommodate workpieces in addition to tools. In particular, no attachments to the holders are necessary to store workpieces. Instead, the tool changer's holders can be used to store either tools or, with the adapters according to the invention, workpieces, without any modifications or additions.

[0032] This not only leads to a significantly simplified design of the arrangement according to the invention, but also ensures that the handling of tools or workpieces is not hindered by such attachments.

[0033] This also makes it possible to use double grippers for intermediate handling of tools or workpieces. This can also be achieved without any additional design modifications, as the interfaces of the double grippers correspond to the interfaces of the machine tool spindle. Therefore, they can be used not only for storing tools but also adapters with or without a workpiece, without any additional effort.

[0034] The method according to the invention can therefore be implemented with conventional machine tools and tool changers without requiring any modifications to these units. The only additional elements required are the workpiece-holding adapters.

[0035] The method according to the invention can therefore be implemented with extremely low investment costs. Furthermore, there are no issues regarding CE conformity, as existing, additional units can be used to carry out the method according to the invention. It is also advantageous that the method according to the invention can readily be applied to different machines. Finally, it is advantageous that no additional space is required to implement the method according to the invention. Moreover, no additional control systems are necessary.

[0036] Generally, a workpiece mounted on an adapter can be fed to or picked up from a machining location by means of the spindle. In this case, a workpiece fixed to an adapter is fed to the machining location by means of the spindle. The workpiece is positioned and set down at the machining location, and the empty adapter is returned to the tool changer.

[0037] For example, a vise can be provided at the machining location, to which a workpiece can be delivered for machining and removed again after machining using an adapter mounted on the spindle.

[0038] Furthermore, the machining location can also be a zero-point clamping system. In this case, a carrier can be attached to the workpiece, which is transported via an adapter. This carrier has an interface for connection to the zero-point clamping system. The adapter, along with the workpiece and the carrier, can then be moved to the zero-point clamping system using the spindle, and the carrier with the workpiece can be placed directly on the zero-point clamping system.

[0039] According to an advantageous embodiment of the invention, adapters are provided for storing different workpieces.

[0040] This results in a further increase in the functionality of the arrangement according to the invention.

[0041] According to an initial proposal, different types of adapters are provided.

[0042] According to a second variant, adapters have adjustment mechanisms, which allow different workpieces to be fixed to them.

[0043] Advantageously, each adapter has fastening means by which a workpiece can be reversibly and releasably attached.

[0044] Magnetic or, particularly advantageously, mechanical fastening means can be used.

[0045] According to a suitable design, the adapter or adapters have two spring-loaded arms between which a workpiece can be attached.

[0046] The two arms thus hold the workpiece on opposite sides. The spring-like properties of the arms facilitate inserting the workpiece between them and removing it from the adapter.

[0047] It is convenient to insert a locking strip into a groove on a side wall of the workpiece on the inside of each arm.

[0048] This ensures simple, stable and reliable storage of the workpiece on the adapter.

[0049] Here, the spring-like properties of the arms can be used to a particularly advantageous advantage, since only the arms need to be slightly widened to insert the workpiece into the adapter or to release it from fasteners.

[0050] The grooves are advantageously incorporated in areas of the workpiece that are excluded from machining with tools.

[0051] This method takes advantage of the fact that areas on two opposite sides of the workpiece are generally excluded from machining processes; that is, they remain undamaged during machining. These areas of the workpiece are therefore used for machining grooves or, more generally, components of fasteners for coupling to the adapter.

[0052] The invention will be explained below with reference to the drawings. The drawings show: Fig. 1: Exemplary embodiment of the arrangement according to the invention in the form of a machining center with a machine tool and a tool changer. Fig. 2: Enlarged detail view of the tool changer according to Fig. 1. Fig. 3: Detailed view of a section of the arrangement according to Fig. 1 when an adapter with a tool changer is handed over to a spindle of the machine tool. Fig. 4: Individual view of an adapter mounted on the spindle of the machine tool with a workpiece attached to it. Fig. 5: Schematic detailed representation of the adapter with workpiece according to Fig. 4. Fig. 6: Illustration of the transfer of an adapter with workpiece from the spindle of the machine tool to a clamping device. Fig. 7: Order according to Fig. 1 when the adapter is detached from the workpiece held in the clamping device.

[0053] Fig. Figure 1 shows an embodiment of the arrangement according to the invention in the form of a machining center 1. The machining center 1 comprises a machine tool 2 with a spindle 2a and an associated tool changer 3 as a storage unit with several identical holders 4 in which tools 5 can be stored, as shown in particular in the detailed illustration of Fig. Figure 2 shows that the tool changer 3's holders 4 are arranged along a path. A conveyor system (not shown) can transport the holders 4, and thus the tools 5 stored therein, to a transfer point where the spindle 2a of the machine tool 2 can pick up a selected tool 5. Similarly, at the transfer point, the spindle 2a can place a tool 5 into a holder 4 of the tool changer 3.

[0054] The machining center 1 further comprises a machine table 6 or a zero-point clamping system where a workpiece 7 can be stored in defined positions so that it can be machined with the tool 5 on the spindle 2a. To hold the workpiece 7 at a defined machining location, a clamping device 8, which can be in the form of a vise, for example, is mounted in a predetermined position on the machine table 6.

[0055] As from the Fig. 1, Fig. 2 to Fig. As can be seen in Figure 3, according to the invention, not only tools 5 but also workpieces 7 can be stored in the receptacles 4 of the tool changer 3. For this purpose, the workpieces 7 are each stored in an adapter 9, as can be seen in particular from the Fig. 4 and Fig. 5 is visible.

[0056] Essentially, the adapter 9 has an interface for connection to the spindle 2a. The spindle 2a has an interface in the form of a gripper groove, which forms a universal interface for connecting different tools 5. According to the invention, the interface of the adapter 9 corresponds to the tool interface, so that the adapter 9 can be used alone or with a workpiece 7 mounted on it (such as the Fig. 1, Fig. 2 to Fig. 3 show) as well as the tools 5 can be picked up with the spindle 2a and can be stored on any mountings 4 of the tool changer 3.

[0057] In order to accommodate different workpieces 7, different types of adapters 9 can be provided, which, however, always have the same interface for connection to the spindle 2a.

[0058] Alternatively or additionally, adjustable adapters 9 can be provided with which different workpieces 7 can be accommodated.

[0059] As from Fig. As can be seen in Figure 4, the adapter 9 is mounted on the spindle 2a with its interface on the top side. A threaded spindle 10 runs parallel to each other on the top side of the adapter 9, and a guide column 11 runs on either side of it. These elements are guided in a guide block 12, on which the interface is located.

[0060] An arm 13 is provided at each of the longitudinal ends of the threaded spindle 10. The identically designed arms 13, arranged symmetrically to the center of the adapter 9, extend downwards perpendicular to the top surface of the adapter 9. The arms 13 are spring-loaded. The distance between the arms 13 can be adjusted by means of the threaded spindle 10.

[0061] As from Fig. 5 A locking strip 14 is provided in the area of ​​the lower edge of each arm 13, extending over almost the entire width of the arm 13. The longitudinal axis of the locking strip 14, which runs along a straight line, is parallel to the plane of the top of the adapter 9.

[0062] The locking strips 14 form mechanical fastening means for fixing a workpiece 7 to the adapter 9. In principle, magnetic fastening means or the like could also be provided.

[0063] Corresponding to the locking strips 14, a groove 15 is machined into opposite sides of a workpiece 7. Advantageously, the grooves 15 are machined by embossing processes.

[0064] When an adapter 9 is placed on a workpiece 7 or when an adapter 9 is removed from the workpiece 7, the spring properties of the arms 13 are utilized, which allows the locking strips 14 to be easily inserted into or removed from the grooves 15.

[0065] For machining center 1 according to Fig. 1 preferably all adapters 9 used there have the same fastening means in the form of the locking strips 14 and all workpieces 7 have the same corresponding grooves 15, so that workpieces 7 can be fixed to any adapters 9.

[0066] Furthermore, it is essential that the grooves 15 are machined at points on the workpieces 7 that are not machined by the tools 5. This ensures that the grooves 15 remain unaffected as connection points to the adapters 9 both before and after workpiece machining.

[0067] As in the Fig. 1 and Fig. As illustrated in Figure 2, tools 5 or adapters 9 with or without workpieces 7 can be stored in the receptacles 4 of the tool changer 3.

[0068] Fig. Figure 3 schematically shows the transfer of an adapter 9 with workpiece 7 at the transfer point from a holder 4 of the tool changer 3 to the spindle 2a.

[0069] Fig. Figure 6 shows the delivery of the workpiece 7, stored in the adapter 9, to the clamping device 8. The workpiece 7 is then fixed in the clamping device 8. The adapter 9 is then released from the workpiece 7 ( Fig. 7).

[0070] The spindle 2a can then store the empty adapter 9 in the tool changer 3. Once the machining operation on the workpiece 7 is completed using a tool 5 (which is also retrieved from the tool changer 3), the spindle 2a retrieves an empty adapter 9 from the tool changer 3 and moves it to the workpiece 7 at the clamping device 8. The adapter 9 is then automatically attached to the workpiece 7. The unit consisting of the adapter 9 and the workpiece 7 can then be placed in the tool changer 3 by moving the spindle 2a.

[0071] The order according to Fig. The machining center 1 can be further developed such that the machine table 6 is configured as a zero-point clamping system. In this case, a workpiece 7 with an attached carrier can be fixed to the adapter 9, the carrier forming an interface for connection to the zero-point clamping system. When the spindle 2a picks up the adapter 9, to which the workpiece 7 is fixed with the carrier, this unit can be transported from the zero-point clamping system by the spindle 2a. The workpiece 7 is then simply fixed in position on the zero-point clamping system by placing the carrier on it.

[0072] Another possible extension of the arrangement according to Fig.1 is the use of double grippers for intermediate handling on the workpiece 7 and tool 5. Since the double gripper has the same interfaces as the spindle 2a, tools 5 or adapters 9 can be optionally fixed to it with or without workpieces 7. Reference symbol list 1 processing center 2 machine tools 2a Spindle 3 tool changers 4 recording 5 tools 6 machine table 7 workpiece 8 clamping devices 9 adapters 10 threaded spindles 11 Leadership pillar 12 Guide block 13 Arm 14 locking strip 15 Nut

Claims

[1] Method for operating an arrangement with a machine tool (2) and a tool changer (3), wherein the tool changer (3) has a number of receptacles (4) in which tools (5) can be inserted by means of a spindle (2a) of the machine tool (2) or tools (5) can be removed from the receptacles (4), characterized by , that adapters (9) are provided to which workpieces (7) can be fixed, wherein the adapters (9) each have an interface for connection to the spindle (2a), and that by means of the spindle (2a) adapters (9) with workpieces (7) fixed to them can be stored in the receptacles (4) of the tool changer (3) or removed from the receptacles (4) of the tool changer (3). [2] Method according to claim 1, characterized by, that adapters (9) can be inserted into or removed from the holders (4) of the tool changer (3) by means of the spindle (2a) without workpieces (7) fixed to them. [3] Method according to claim 1 or 2, characterized by , that at least one double gripper is provided for carrying out intermediate handling, on which either workpieces (7) or adapters (9) with or without workpieces (7) can be stored. [4] Method according to any one of claims 1 to 3, characterized by , that a workpiece (7) stored on the adapter (9) is fed to or picked up from a machining location by means of the spindle (2a). [5] Method according to any one of claims 1 to 4, characterized by , that a support is attached to a workpiece (7) fixed to an adapter (9), which has an interface for connection to a zero-point clamping system. [6] Method according to one of claims 4 or 5, characterized by , that a workpiece (7) fixed to an adapter (9) is fed to the machining location by means of the spindle (2a), that the workpiece (7) is then positioned and placed at the machining location, and that the empty adapter (9) is fed back to the tool changer (3). [7] Arrangement comprising a machine tool (2) and a tool changer (3), wherein the tool changer (3) has a number of holders (4) in which tools (5) can be inserted by means of a spindle (2a) of the machine tool (2) or tools (5) can be removed from the holders (4), characterized by, that adapters (9) are provided to which workpieces (7) can be fixed, wherein the adapters (9) each have an interface for connection to the spindle (2a), and that by means of the spindle (2a) adapters (9) with workpieces (7) fixed to them can be stored in the receptacles (4) of the tool changer (3) or removed from the receptacles (4) of the tool changer (3). [8] Arrangement according to claim 7, characterized by that adapters (9) are provided for storing different workpieces (7). [9] Arrangement according to claim 8, characterized by , that different types of adapters (9) are provided. [10] Arrangement according to one of claims 8 or 9, characterized by that adapters (9) have adjustment mechanisms, which allow different workpieces (7) to be fixed to them. [11] Arrangement according to any one of claims 7 to 10, characterized by, that the or each adapter (9) has fastening means by which a workpiece (7) can be reversibly and detachably fastened. [12] Arrangement according to any one of claims 7 to 11, characterized by that the adapter (9) has two spring arms (13) between which a workpiece (7) can be attached. [13] Arrangement according to claim 12, characterized by , that a locking strip (14) can be inserted into a groove (15) on a side wall of the workpiece (7) on the inside of each arm (13). [14] Arrangement according to claim 13, characterized by , that the grooves (15) are incorporated in areas of the workpiece (7) which are excluded from machining with tools (5).

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