Tool magazine, machine tool and method for changing tools

Abstract

The present invention relates to a tool magazine, a machine tool with such a tool magazine, and a method for changing tools in this machine tool, in which the tool location occupancy can be optimized during operation with regard to the resulting waiting times and cycle times of the machine tool. A basic idea of ​​the invention is to utilize the transport paths already required for clearing a previously used tool to transport this tool to a suitable location—a preferred location with shorter transport times—in order to gradually reduce future waiting times of the work spindle.

Description

[0001] The invention relates to tool magazines for accommodating a plurality of tools with a plurality of tool locations, to machine tools having such a tool magazine, and to methods for changing tools in a machine tool. In particular, the present invention relates to a possibility for optimizing tool location utilization during ongoing operation of the machine tool.

[0002] Machine tools are well known in the art. In machine tools, workpieces are machined using (different) tools. The workpiece is usually machined in a sequence of several processing steps, which is also referred to below as a processing cycle. Different tools are required for the various processing steps. The various tools are made available to the machine tool in tool magazines. Once processing with the current tool is completed, a tool change takes place, e.g., with a tool changer in a tool change station. The transport times between the tool magazine and the tool change station can vary (considerably) depending on the tool location in the tool magazine.

[0003] EP 3 929 680 A1 describes an optimization process in which the space allocation of the individual tools in the tool magazine is optimized before machining the workpiece in such a way that tool change times are minimized.

[0004] WO 2022 / 096087 A1 also describes a method for the computer-aided optimization of tool transports for at least a plurality of magazine locations in the tool magazine. Here, too, after all tools and the space requirements for each tool have been recorded, a re-sorting process is performed before the actual machining of the workpiece.

[0005] The approaches described in the prior art for optimizing the occupancy of tools in a tool magazine have the disadvantage that for each machining program run, an optimization of the tool magazine occupancy must first be calculated in a complex manner and then carried out in a re-sorting process, which reduces the effective time in which workpieces can be machined with the machine tool and increases the unproductive times of the machine tool.

[0006] Based on this, the object of the invention is to provide an improved concept for optimizing the utilization of tool magazines in machine tools, in which in particular the effective time in which workpieces can be machined with the machine tool is increased and the unproductive times of the machine tool are reduced.

[0007] This object is achieved with the tool magazine according to claim 1, the control device according to claim 13, the machine tool according to claim 14, the method according to claim 15, the computer program according to claim 16 and the computer-readable medium according to claim 17: The tool magazine according to the invention serves to accommodate a plurality of tools with a plurality of tool positions, of which a predetermined number are priority positions. The tool magazine has a transport device and a control device. The transport device is designed to transport tools from the tool positions to a tool change station and vice versa, wherein the transport time between the priority positions and the tool change station is shorter than the transport time between the remaining tool positions and the tool change station.The control device is designed to control the transport device and to record a usage time of each tool used and a transport time during which a previously used tool is removed, i.e., transported from the tool change station to one of the tool locations, and a subsequently used tool is prepared, i.e., transported from one of the tool locations to the tool change station. The control device is designed to assign a preferred location to a subsequently used tool during production operation—i.e., while a workpiece is being machined with a currently used tool—if the transport time is greater than the usage time of a currently used tool.

[0008] This makes it possible to optimize the tool magazine while the machine tool is in operation, i.e. while workpieces are being machined using the tools from the tool magazine in a machine tool, without the need for prior optimization with a separate program run. The optimization can take place during ongoing production. Furthermore, the tool assignment of the tool magazine can be optimized without the need for information about the running machining program, such as the sequence of individual machining steps, workpiece types, number of workpieces, tool types, number of tools, or similar. In addition, the optimization during ongoing operation described here eliminates the need for complex and computationally intensive pre-optimization, which incorporates a large number of parameters, such as the transport times for each individual storage location.These properties are otherwise determined in complex test runs or simulated in advance.

[0009] A special feature of the present invention is that the transport paths required anyway for clearing a previously used tool are used to transport the previously used tool to a suitable location, a priority location, in order to avoid future waiting times for the work spindle. Waiting times can thus be successively reduced, which can shorten the cycle time of the machine tool, since optimized tool loading in the tool magazine can be carried out automatically during operation without additional user intervention. Especially with repetitive machining cycles of the machine tool, optimized tool loading of the tool magazine can be achieved without additional effort.

[0010] The usage time is the time during which a tool is actually used in the machine tool, for example, in a machining process, during positioning, or during a measuring operation. During a measuring operation, the tool can be a measuring probe that can be inserted into the work spindle. The transport time of a subsequently used tool is specifically defined as the sum of the clearing time during which a previously used tool is transported from the tool change station to one of the tool locations and the preparation time during which a subsequently used tool is transported from one of the tool locations to the tool change station.Since the transport time includes both the clearing time and the preparation time of two different tools, namely the previously used tool and the subsequently used tool, the previously used tool and / or the subsequently used tool can be the cause of a waiting time. However, since the previously used tool has already been cleared when the waiting time is determined, the space occupancy of the subsequently used tool is optimized first; this tool is only cleared after it has been used. The previously used tool is marked for optimization and will be optimized in the next machining cycle.

[0011] Preferably, the control device is configured to control the transport device independently of information about the currently executing machining cycle, in particular independently of information about the sequence of tools used in the currently executing machining cycle. The optimization of tool location occupancy occurs successively, without the need for complex pre-optimization.

[0012] In particular, the control device is configured to determine a waiting time for the subsequently used tool from the clearing time of the previously used tool, the provision time of the subsequently used tool, and the usage time of the currently used tool. In particular, this is determined using the following formula: T_w(n)=T_a(n−2)+T_b(n)−T_v(n−1), where T_w (n) is the waiting time for the subsequently used tool, T_a (n-2) is the clearing time of the previously used tool, T_b (n) is the provision time of the subsequently used tool and T_v (n-1) is the usage time of the currently used tool.

[0013] The control device is particularly configured to assign a preferred location to the subsequently used tool if its waiting time is positive. The tool location of the subsequently used tool is only optimized if the waiting time is positive.

[0014] The control device is preferably configured to assign one of the remaining tool locations to the subsequently used tool if all preferred locations are occupied. Of the plurality of tool locations, only a predetermined number of preferred locations are available. If all preferred locations are occupied, a tool with greater time savings can be replaced by a tool with lower time savings for further optimization. The control device can further be configured to control the transport device in such a way that it changes the tool assignment in the tool magazine acyclically or asynchronously if a (sufficient) negative waiting time exists. In the case of an acyclic change to the tool assignment in the tool magazine, the tool assignment in the tool magazine can be changed between two consecutive machining cycles.In the case of an asynchronous change in the tool assignment in the tool magazine, previously used tools can be placed in an optimized tool location before the next cycle and tools that are placed in preferred locations but for which there is no need for optimization can be transported (back) to one of the remaining tool locations.

[0015] The control device is particularly designed to initiate a change in the tool allocation using the transport device, whereby a tool to be transferred is to be transported by means of the transport device from one of the priority locations to one of the remaining tool locations if all priority locations are occupied, if there is a (sufficient) negative waiting time, and if at least one of the following criteria is met: - The tool to be moved was not used in the previous machining cycle; - The tool to be moved was not used in the current machining cycle; and - The tool to be moved has not been used for a longer time than the other tools arranged in the priority positions.

[0016] The transfer of tools from the preferred locations to the remaining tool locations is referred to as asynchronous optimization if it occurs during a sufficiently high, negative wait time. Such asynchronous optimization can be performed whenever the current tool is required for a (sufficiently) long period of use in the current machining step.

[0017] The tool magazine is, in particular, a rack magazine that has at least one preferred magazine and at least one base magazine, preferably a plurality of base magazines. The transport times of a tool between the preferred magazine and the tool change station are shorter than the transport times of a tool between the base magazine(s) and the tool change station.

[0018] The control device is preferably configured to specify a predetermined preferred transport time for all preferred positions and / or a predetermined base transport time for all other tool positions. This simplifies the optimization calculations because the preferred transport time and the base transport time are fixed, pre-estimated or determined values.

[0019] Alternatively, the control device can be configured to divide the tool magazine's multiple tool locations into zones and to specify predetermined zone transport times for the individual tool locations within the zones. This alternative approximates reality through the definition of the zones and represents a compromise between realism and simplicity.

[0020] In another alternative, the control system is configured to record and determine an individual transport time for each tool location. This alternative is closest to reality, so the optimization result for tool location utilization is likely to be the best.

[0021] The control device is particularly designed to retain previously made assignments of tools that were transported to a preferred location after use in the work spindle in a current machining cycle or the previous machining cycle, thereby avoiding constant re-optimization in the current machining cycle.

[0022] Preferably, the controller is configured to initiate a transport of at least one tool from a preferred location to one of the remaining tool locations or vice versa if the previously determined waiting time is sufficiently negative (asynchronous optimization).

[0023] The object of the invention is also achieved with a control device for a tool magazine of the above type. The control device according to the invention is designed to, during production operation, ie while a workpiece is being machined with a currently used tool, - Record the usage time of each tool used; - A transport time that a clearing time in which a previously used tool is transported from the tool changing station to one of the tool stations and a preparation time in which a subsequently used tool is transported from one of the tool stations to the tool change station; and - To assign a priority position to a subsequently used tool if its transport time is greater than the usage time of a currently used tool.

[0024] All features and advantages mentioned in connection with the tool magazine according to the invention also apply to the control device according to the invention.

[0025] The object of the invention is further achieved by a machine tool with a tool magazine of the above type and with a work spindle, wherein the work spindle is designed to receive a tool provided at the tool changing station and to machine the workpiece with this tool, in particular by machining.

[0026] The object of the invention is also achieved by the method according to the invention for changing tools in a machine tool, in particular of the above type, in production operation, ie while a workpiece is being machined with a tool currently in use, the method comprising the following steps: - Recording the usage time of each tool used; - Recording a transport time that a clearing time in which a previously used tool is transported from the tool changing station to one of the tool positions, and a preparation time during which a subsequently used tool is transported from one of the tool stations to the tool change station; and - Assigning a priority location for a subsequently used tool if its transport time is greater than the usage time of a currently used tool.

[0027] The features and advantages described with respect to the tool magazine according to the invention and in particular with respect to the control device according to the invention are also applicable to the method according to the invention.

[0028] Furthermore, the object is achieved by a computer program and a computer-readable medium comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method of the above type.

[0029] Further details of advantageous developments or details of the invention can be found in the drawings, the description, and the dependent claims. They show: Fig. 1 A schematic perspective view of an embodiment of a machine tool with a tool magazine according to the invention; Fig. 2 A flow chart for an embodiment of the method according to the invention; Fig. 3 A flowchart for an example to determine the need for optimization; and Fig. 4 A flowchart showing an example of the method for controlling the tool magazine.

[0030] Fig. 1 shows a concrete type of tool magazine 10, namely a tool magazine rack. Fig. However, the tool magazine shown in Figure 1 can represent any type of tool magazine in which the inventive concept can be implemented with a plurality of tool positions, of which a predetermined number are preferred positions, with a transport device and a control device for optimizing the tool position occupancy.

[0031] The Fig. 1 is used to hold a plurality of tools 11. The tool magazine 10 has a plurality of tool positions 12 in which the tools 11 can be stored. In Fig. 1, the tool magazine 10 has a priority magazine with 20 priority positions 19 and four base magazines with a total of 90 remaining tool positions 12. The total number of tool positions is 110. The number of priority positions 19 and the number of remaining tool positions 12 can be any number.

[0032] The tool magazine 10 also has a transport device 13 which is designed to transport the tools 11 from the tool stations, i.e. from the priority stations 19 and also the other tool stations 12, to a tool changing station 14 and vice versa.

[0033] The Fig. The transport device 13 shown as an example in Figure 1 comprises a movable carriage 15, a column 16 arranged thereon with a height-adjustable and pivotable arm 17, at the end of which a tool holder 18 is arranged. The arm 17 with the tool holder 18 has two pivot axes. The transport device 13 is designed to take tools 11 from the tool stations, namely from the priority stations 19 and the remaining tool stations 12, with the tool holder 18, and transport them to the tool changing station 14.

[0034] The tool magazine 10 has a predetermined number of priority locations 19, the transport time of which, ie the time in which a tool 11 is transported by the transport device 13 from one of the priority locations 19 to the changing station 14 and vice versa, is shorter than the transport time of the remaining tool locations 12, ie the time in which a tool 11 is transported by the transport device 13 from the remaining tool locations 12 to the tool changing station 14 and vice versa.

[0035] In the Fig. In the example shown in Figure 1, the priority magazine with the priority positions 19 is the shelf magazine, in which the tools stored therein are already aligned so that they can be transported to the tool changing station 14 without pivoting using the transport device 13. The pivoting process of the transport device 13 can be time-consuming. In the case of the basic magazines with the remaining tool positions 12, Fig. 1 a swiveling operation is necessary in order to transport a tool 11 from one of the other tool stations 12 to the changing station 14 and vice versa.

[0036] The tool magazine 10 also has a control device 20 configured to control the transport device 13. The control device 20 is further configured to record a usage time of each tool used and a transport time during which a previously used tool 21 is removed and a subsequently used tool 22 is provided. The setup process refers to the pair of the previously used tool 21 and the subsequently used tool 22.

[0037] Removing a previously used tool 21 means that the previously used tool 21 is transported from the tool change station 14 to a preferred location 19 or one of the remaining tool locations 12. Providing a subsequently used tool 22 means that the subsequently used tool 22 is transported from one of the preferred locations 19 or one of the remaining tool locations 12 to the tool change station 14.

[0038] The control device 20 is configured to assign a preferred location 19 to a subsequently used tool 22 if its transport time is greater than the usage time of a currently used tool 23. By assigning a preferred location 19 to a subsequently used tool 22 if its transport time is greater than the usage time of the currently used tool 23, the occupancy of the tool magazine 10 can be optimized during operation such that the waiting time for the machine tool 24 having such a tool magazine 10 is as short as possible. This optimization takes effect when the tool 11 deposited by the control device 20 in a preferred location 19 is used again.

[0039] The machine tool 24 has a work spindle 25 which is designed to receive one of the tools 11 and to machine a workpiece 27 arranged on a workpiece table 26. Irrespective of the inventive concept for optimizing the space occupancy in the tool magazine 10, the machine tool 24 can be a three-axis, four-axis, or five-axis machine tool. Fig. The machine tool 24 shown in Figure 1 is a five-axis machine tool 24 with the axes X, Y, Z, A and B. The unit consisting of the machine tool 24 and the tool magazine 10 can also be referred to as a machining center.

[0040] In the Fig. 1, a currently used tool 23 is clamped in the work spindle 25. The previously used tool 21 has already been placed on one of the priority positions 19 by the transport device 13. The transport device 13 is in the Fig. 1, a subsequently used tool 22 is picked up from one of the remaining tool positions 12 of the base magazine and transported to the tool changing station 14.

[0041] In Fig. 1, an oversized tool 28 is also stored in the tool magazine 10. The oversized tool 28 occupies several tool locations 12. The control device 20 is configured to suspend the optimization of the location occupancy for such oversized tools 28.

[0042] The Fig. The tool changing station 14 shown in Figure 1 has a rotary changer 29 configured to receive a currently used tool 23 from the work spindle 25 and a subsequently used tool 22 from the transport device 13, and preferably to exchange them by rotating both, so that the subsequently used tool 22 can be received and used by the work spindle 25. At the same time, the transport device 13 with the tool holder 18 can receive the previously used tool 21 from the rotary changer 29 and transport it to one of the tool positions 12 of the tool magazine 10.

[0043] Fig. 2 schematically illustrates the chronological sequence of the process steps of the work spindle 25 and the transport device 13. The chronological sequence of the work spindle 25 is shown in the upper line of Fig. 2, while the time sequence of the transport device 12 is shown in the lower line of Fig. 2. The usage time 30 is the time during which a currently used tool 23 is clamped in the work spindle 25 and during which the workpiece 27 is machined by the work spindle 25 with the currently used tool 23.

[0044] In the Fig. In the example shown in Figure 2, tools WZ1, WZ2, WZ3, WZ4, and WZ5 are used in this order. Between the usage times 30 of the individual tools WZ1, WZ2, WZ3, WZ4, and WZ5, the work spindle 25 is idle for a tool change time 31.

[0045] During the usage time 30 in which the workpiece 27 is being machined with the work spindle 25, the subsequently used tool 22 can already be prepared by the transport device 13. This occurs during the transport time 32. The transport time 32 includes a clearing time 33, namely the time in which the previously used tool 21 is transported by the transport device 13 to one of the tool locations 12 of the tool magazine 10. The transport time 32 also includes a preparation time 34 in which the subsequently used tool 22 is transported by the transport device from one of the tool locations 12 to the tool change station 14.

[0046] The difference between usage time 30 and transport time 32 results in waiting time 35. During a positive waiting time 35, the work spindle 25 cannot be used because it is necessary to wait until the subsequently used tool is provided by the transport device 13. If usage time 30 is greater than the transport time, a negative waiting time 35 results, which can be used for acyclic optimization of the occupancy of the tool magazine 10.

[0047] In the Fig. In the example shown in Figure 2, a positive waiting time 35 results in the machining step in which the third tool WZ3 is used. Due to the positive waiting time 35 in the machining step in which the third tool WZ3 is used, the control device 20 assigns a preferred location 19 in the tool magazine 10 to the subsequently used tool 22, namely the fourth tool WZ4. After the usage time 30 of the fourth tool WZ4 has elapsed, the transport device 13 transports it from the tool change station 14 to a preferred location 19 in the machining step in which the fifth tool WZ5 is used.

[0048] In Fig. 2 also shows an example in which a negative waiting time occurs in the machining step in which the second tool WZ2 is used. In this example, however, the negative waiting time 35 is not so long that the tool assignment can be changed asynchronously. In the machining step in which the fourth tool WZ4 is used, however, the negative waiting time is sufficiently long. In the time difference between the usage time 30 of the fourth tool WZ4 and the transport time 32 of the fifth tool WZ5, the transport device 13 is controlled by the control device 20 such that the tool assignment of the tool magazine 10 is changed in a reordering time 36.

[0049] Fig. 3 shows an example of a method or routine for determining the need for optimization of the tool occupancy of the tool magazine 10. In a first query step 37, it is determined whether the waiting time 35 for the subsequently used tool 22 is positive, i.e., greater than 0. If this is the case, a second query 38 determines whether the subsequently used tool 22 has already been optimized. If the subsequently used tool 22 has not yet been optimized, a first process step 39 assigns the subsequently used tool 22 a preferred location 19 in the tool magazine 10. This means that the subsequently used tool 22, after being used in the work spindle 25, is transported from the tool changing station 14 to one of the preferred locations 19 by means of the transport device 13.

[0050] A positive waiting time 35 can result, on the one hand, from an excessively long clearing time 33 of the previously used tool 21 and, on the other hand, from an excessively long preparation time 34 of the subsequently used tool 22. The method or routine can therefore contain a third query 40 in which a check is carried out in the subsequent machining cycles as to whether the waiting time for the subsequently used tool still exists. If this is not the case, the optimization for this tool is terminated. If a positive waiting time still exists, a fourth query 41 determines whether the previously used tool 21 has already been optimized. If the previously used tool 21 has not yet been optimized, i.e. none of the preferred locations 19 has been assigned to it, a preferred location 19 can be assigned to the previously used tool 21 in the second process step 42.In this case, the previously used tool 21 is reserved to be transported to one of the priority locations 19 when this tool is used again.

[0051] Alternatively, if the negative waiting time is sufficiently long, the tool marked in this way can be transported to one of the priority locations 19 by the transport device 13 (asynchronous re-sorting). If the previously used tool 21 has already been optimized, i.e., one of the priority locations 19 has already been assigned to the previously used tool 21, the optimization for the pair consisting of the previously used tool 21 and the subsequently used tool 22 is terminated.

[0052] If a negative waiting time 35 was determined in the first query 37, a query is made as to whether the subsequently used tool 22 has already been assigned a preferred location 19, i.e. whether the subsequently used tool 22 has already been optimized (fifth query 43). If the subsequently used tool 22 has already been optimized, a subroutine can now be used to determine whether it is possible to clear some of the preferred locations 19 in the preferred magazine of the tool magazine 10, i.e. to transport tools 11 that are stored in a preferred location 19 from the preferred location 19 to one of the remaining tool locations 12 in the base magazine of the tool magazine 10. For this purpose, a sixth query 44 determines whether a positive waiting time would result if the subsequently used tool 22 were not stored in one of the preferred locations 19. If a positive waiting time would result, the location allocation is retained.In the event that no positive waiting time would arise, a preferred position 19 is assigned to the subsequently used tool 22 in a third process step 47.

[0053] The method can then consist in a further program section in which it is first checked whether the previously used tool 21 has already been optimized (seventh query 45). If this is not the case, the optimization for the tool pair is ended. If the previously used tool 21 has already been optimized, an eighth query 46 determines whether a positive waiting time would result if the previously used tool were not placed in one of the preferred locations 19, but rather in one of the remaining tool locations 12. If a positive waiting time would result, the previously used tool 21 remains assigned to one of the preferred locations 19; if no positive waiting time would result, a tool location 12 of the remaining tool locations 12 of the tool magazine 10 is assigned to the previously used tool 21 in a fourth process step 48.

[0054] The program sections triggered in the fifth query 43 and the seventh query 45 are optional and serve to generate free priority slots 19. This prevents all priority slots 19 from being occupied, thus blocking optimization during operation.

[0055] Fig. Figure 4 shows a flowchart for an example of a method for optimizing previously removed tools. This program section concerns the case where a previously used tool 21 has already been stored in the tool magazine 10, and optimization of the space allocation for the previously used tool 21 is only possible after the next machining step in which the tool is used.

[0056] Alternatively, the previously used and already stored tool 21 can be relocated if a sufficiently long, negative waiting time occurs (asynchronous relocation). However, the relocation of the previously used tool can take place in the next machining cycle at the latest, if a large number of identical work cycles are executed consecutively.

[0057] After starting the program section, a query is made as to whether one of the requirements for optimization is met (first program query 49). If no requirements for optimization are met, the current tool is transported back to its previous tool location 12 in the tool magazine 10 (first program step 50). If at least one of the requirements for optimization is met, an optimization requirement is determined (second program step 51). The determination of the optimization requirement can be carried out in particular according to the method from Fig. 3 happened.

[0058] After the optimization requirement has been determined, a second program query 52 queries whether optimization is required. If this is not the case, the tool is transported to its existing tool location, which is one of the remaining tool locations 12 (third program step 53). If optimization is required, a fourth program step 54 searches for a free tool location in the preferred magazine with the preferred locations 19 and reserves it for the tool to be optimized.

[0059] A third program query 55 queries whether any preferred locations 19 are free in the tool magazine 10. If this is not the case, a fifth program step 56 determines whether a tool 11 is present at a preferred location 19 and can be moved to one of the remaining locations 12. If such a tool was determined in a third program query 57, the determined tool is transported from its preferred location 19 to one of the remaining tool locations in a sixth program step 58, and the program returns to the fourth program step 54. If no such tool was determined, optimization is not possible, so that in a seventh program step 59 the tool is transported to its existing tool location, which is one of the remaining tool locations 12.

[0060] If it was determined in the third program query 55 that a free priority location 19 exists, the tool is transported to this priority location 19 in an eighth program step 60.

[0061] The present invention relates to a tool magazine, a machine tool 24 having such a tool magazine 10, and a method for changing tools 11 in this machine tool 24, in which the tool location occupancy can be optimized during operation with regard to the resulting waiting times and cycle times of the machine tool. The transport paths required anyway to clear a previously used tool can be used to transport the previously used tool to a suitable location, a priority location, in order to avoid future waiting times for the work spindle. The waiting times can thus be successively reduced, whereby the cycle time of the machine tool can be reduced, since optimized tool occupancy in the tool magazine can take place automatically during operation without additional user intervention.Especially with repetitive machining cycles of the machine tool, an optimized utilization of the tool magazine can be achieved without additional effort. Reference symbol: 10 tool magazine 11 tools 12 tool stations 13 Transport device 14 tool changing station 15 sleds 16 Column 17 Arm (swivel arm) 18 Tool holder 19 priority seats 20 Control device 21 previously used tool 22 tool used below 23 currently used tools 24 machine tools 25 work spindle 26 Workpiece table 27 Workpiece 28 oversized tools 29 rotary changers 30 usage time 31 Tool change time 32 Transport time 33 Clearance time 34 staging area 35 waiting time 36 Reordering time 37 first query 38 second query 39 first process step 40 third query 41 fourth query 42 second process step 43 fifth query 44 sixth query 45 seventh query 46 eighth query 47 third process step 48 fourth process step 49 first program query 50 first program step 51 second program step 52 second program query 53 third program step 54 fourth program step 55 third program query 56 fifth program step 57 fourth program query 58 sixth program step 59 seventh program step 60 eighth program step A A-Axis (rotation axis) B B-axis (rotation axis) X X-axis Y Y-axis Z Z-axis WZ1 first tool WZ2 second tool WZ3 third tool WZ4 fourth tool WZ5 fifth tool QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3 929 680 A1

[0003] WO 2022 / 096087 A1

[0004]

Claims

[1] Tool magazine (10) for receiving a plurality of tools (11) with a plurality of tool positions (12), of which a predetermined number are preferred positions (19), comprising: a transport device (13) which is designed to transport tools from the tool stations (12) to a tool changing station (14) and vice versa, wherein a transport time between the priority stations (19) and the tool changing station (14) is shorter than a transport time between the other tool stations (12) and the tool changing station (14); a control device (20) for controlling the transport device (13) and for detecting a usage time (30) of each tool (11) used and a transport time (32) in which a previously used tool (21) is removed, i.e. transported from the tool changing station (14) to one of the tool stations (12), and a subsequently used tool (22) is provided, i.e. transported from one of the tool stations (12) to the tool changing station, wherein the control device is designed to allocate a preferred location (19) to a subsequently used tool (22) during production operation, ie while a workpiece (27) is being machined with a currently used tool (23), if its transport time (32) is greater than the usage time (30) of the currently used tool (23). [2] Tool magazine (10) according to claim 1, characterized bythat the transport time (32) of a subsequently used tool (22) is the sum of a clearing time (33) in which a previously used tool (21) is transported from the tool changing station (14) to one of the tool locations (12), and a preparation time (34) in which a subsequently used tool (22) is transported from one of the tool locations (12) to the tool changing station. [3] Tool magazine (10) according to claim 1 or 2, characterized by that the control device (20) is designed to control the transport device independently of information about the currently executed machining cycle, in particular independently of information about a sequence of the tools used in the currently executed machining cycle. [4] Tool magazine (10) according to one of the preceding claims, characterized bythat the control device (20) is designed to determine a waiting time (35) for the subsequently used tool from the clearing time (33) of the previously used tool (21), the provision time (34) of the subsequently used tool (22) and the usage time (30) of the currently used tool, in particular by means of the following formula: T_w(n)=T_a(n-2)+T_b(n)−T_v(n−1). [5] Tool magazine (10) according to one of the preceding claims, characterized by that the control device (20) is designed to assign a priority position (19) to the subsequently used tool (22) if its waiting time (35) is positive. [6] Tool magazine (10) according to one of the preceding claims, characterized by that the control device (20) is designed to assign one of the remaining tool positions (12) to the subsequently used tool (22) if all preferred positions are occupied. [7] Tool magazine (10) according to one of the preceding claims, characterized by that the control device (20) is designed to transport a tool to be transferred from one of the priority positions (19) to one of the remaining tool positions (12) by means of the transport device (13) if all priority positions are occupied and if at least one of the following criteria is met: - the tool to be moved was not used in the previous machining cycle; - the tool to be moved was not used in the current machining cycle; and - the tool to be moved has not been used for a longer time than the other tools (11) arranged on the priority positions (19). [8] Tool magazine (10) according to one of the preceding claims, characterized bythat the control device (20) is designed to define a predetermined preferential transport time for all preferential positions (19) and / or a predetermined basic transport time for all other tool positions (12). [9] Tool magazine (10) according to one of claims 1 to 7, characterized by that the control device (20) is designed to divide the plurality of tool positions (12) of the tool magazine (10) into different zones and to define predetermined zone transport times for the individual tool positions (12) of the different zones. [10] Tool magazine (10) according to one of claims 1 to 7, characterized by that the control device (20) is designed to determine an individual transport time for each tool location (12). [11] Tool magazine (10) according to one of the preceding claims, characterized bythat the control device (20) is designed to maintain previously made assignments of tools which were transported to a preferred location (19) after use in a current machining cycle. [12] Tool magazine (10) according to one of the preceding claims, characterized by that the control device (20) is designed to initiate a transport of at least one tool from a priority location (19) to one of the remaining tool locations (12) or vice versa if the previously determined waiting time (35) is sufficiently negative. [13] Control device (20) for a tool magazine according to one of the preceding claims, which is designed to, in production operation, ie while a workpiece (27) is being machined with a currently used tool (23), - to record a usage time (30) of each tool (11) used; - a transport time (32) which a clearing time (33) in which a previously used tool (21) is transported from the tool changing station (14) to one of the tool stations (12), and a provision time (34) in which a subsequently used tool (22) is transported from one of the tool stations (12) to the tool changing station; and - to assign a priority position (19) for a subsequently used tool (22) if its transport time (32) is greater than the usage time (30) of the currently used tool (23). [14] Machine tool (24) with a tool magazine (10) according to one of the preceding claims and with a work spindle (25) which is designed to receive a tool (11) provided at the tool changing station (14) and to machine the workpiece (27), in particular by cutting, with this tool (11). [15] Method for changing tools in a machine tool (24), in particular according to claim 14, in production operation, ie while a workpiece (27) is being machined with a currently used tool (23), comprising: - recording a usage time (30) of each tool (11) used; - Recording a transport time (32) which a clearing time (33) in which a previously used tool (21) is transported from the tool changing station (14) to one of the tool stations (12), and a preparation time (34) in which a subsequently used tool (22) is transported from one of the tool stations (12) to the tool changing station; and - Assigning a priority location (19) for a subsequently used tool (22) if its transport time (32) is greater than the usage time (30) of the currently used tool (23). [16] A computer program comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of claims 15. [17] A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of claims 15.

Images