System and method for inserting or removing cutting inserts from a cutting tool

Description

TECHNICAL FIELD

[0001] The invention relates to a system and a method for inserting or removing cutting inserts from tools. BACKGROUND OF THE INVENTION

[0002] Tools for machining workpieces often have interchangeable cutting inserts. These are attached to a cutting tool where they form cutting edges. The cutting tool can be rigid, for example in the form of a turning tool, or movable, particularly rotatable, such as a milling head, on a machine tool. Such cutting inserts wear out during machining and must be replaced regularly. Depending on the size of the cutting tool and the cycle speed of the machine tool, it may be necessary to remove the cutting tool from the machine tool and then replace one or more of the cutting inserts attached to it. During the exchange, the machine tool could accommodate another cutting tool and continue machining in the meantime.

[0003] When examining cutting inserts, the insert is checked for wear. If a certain tolerance is exceeded, the insert is removed from the cutting tool and, for example, in the case of an indexable insert, turned or replaced. During turning, its orientation is changed, and an alternative, unworn cutting edge is aligned in the cutting direction. If all cutting edges on the insert are worn, a new insert is attached.

[0004] Such a process is complex and not ergonomically feasible manually for larger cutting tools. Automated handling of cutting tools for replacement is practically impossible, as cutting inserts are fragile due to their hardness and, due to their often small size, difficult to align and secure without jamming.

[0005] According to the abstract available on Espacenet, a tool in which a reference cutting edge and a reference positioner are attached to a milling tool mounted on a changeover table; a cutting edge tip is automatically exchanged using a gripping hand and a screwdriver. The positions of the gripping hand and screwdriver are controlled so that they can be safely removably attached. After a new cutting edge tip replaces the used one, the axial deflection of the cutting edge is measured by a cutting edge deflection measuring sensor. The cutting edge whose deflection exceeds the tolerance is corrected by using a cutting edge positioning stopper.

[0006] JP H03 196928 A, according to the abstract available on Espacenet, describes a tool in which a cleaned tip prepared at its feeding part is picked up by an insertion machine, and a tip pocket is indexed at the tip removal point, where the approach of each other element is carried out by driving a table.

[0007] US 2016 / 297013 A1, according to the abstract available on Espacenet, describes a device for exchanging machining inserts on a tool, comprising a body and a head carrying at least one machining insert, each plate being held thereon. SUMMARY OF THE INVENTION

[0008] It is therefore an object of the invention to provide a system and a method for

[0009] To propose inserting or removing cutting inserts of a cutting tool, which preferably enable a largely automated exchange of cutting inserts.

[0010] This object is achieved by a system having the features of independent claim 1 and by a method having the features of independent claim 9. Advantageous embodiments and further developments can be found in the subclaims and the following description.

[0011] A system for inserting or removing cutting inserts of a cutting tool according to claim 1 is proposed, comprising a first processing device, a second processing device, and a controller coupled to the first processing device and the second processing device, wherein the first processing device has a gripping element for holding or securing a cutting insert, wherein the second processing device has a fastening tool for fastening or releasing a fastening means holding the cutting insert, and wherein the controller is designed to control the first processing device to hold the cutting insert and to control the second processing device, with the cutting insert held, to fasten or release the fastening means.

[0012] The first processing device and the second processing device are therefore both coupled to the controller and cooperate in the insertion and removal of cutting inserts of a cutting tool. The first processing device is provided to hold or secure a cutting insert, while the second processing device releases or fastens the held or secured cutting insert. The first processing device can therefore always ensure correct alignment of the cutting insert, so that the second processing device establishes or releases its fastening. Tilting-free insertion and fastening is thus possible. The risk of damage when removing the cutting insert can also be significantly reduced by holding it with the first processing device.

[0013] In this context, a cutting insert is defined as an element that can be brought into direct contact with the workpiece in question in order to machine the workpiece. This can be, for example, a cutting insert, particularly an indexable insert. This insert is attached to the cutting tool by a suitable holder.

[0014] In one fundamentally possible embodiment, it is conceivable that the first processing device and the second processing device are arranged near the machine tool in question or are able to reach it as needed. However, it can be provided that the cutting insert is replaced at another location that is independent of the machine tool. For this purpose, it is conceivable that cutting tools from one or more machine tools are brought onto a transport device in order to transport them to another location where the cutting inserts are replaced. The cutting tool could be removed from the machine tool manually and / or semi-automatically and / or fully automatically and transported to the designated position.

[0015] The gripping element of the first processing device is preferably designed to hold the cutting insert so that the second processing device can actuate the fastening means. The holding process is to be understood as meaning that the first processing device holds the cutting insert in a predetermined spatial position. Furthermore, the first processing device can be designed to position the cutting insert such that it can assume a position and orientation intended for interaction with the second processing device. When fastening the fastening means, the first processing device could be designed to compensate for smaller forces acting on the cutting insert when inserting the fastening means into a bore or the like.

[0016] The gripping element, which can be mechanically coupled to the cutting insert, is provided to hold the cutting insert. Many different designs of the gripping element are conceivable for this task. For example, movable members enclosing a gap between them are conceivable, which, when moved, can enclose or clamp the cutting insert between them. Alternatively, elements based on fluid technology, such as suction cups or similar, can be used.

[0017] The second processing device is provided to actuate a fastening means. This can be a clamping and / or screwing device designed to hold the cutting insert on the cutting tool in such a way that the cutting insert remains securely on the cutting tool during operation of the machine tool and the corresponding loads acting on the cutting insert. It can further be provided that the second processing device is designed to measure and / or limit forces or torques applied during fastening of the fastening means. For example, the second processing device could have a screwdriving device designed to screw the fastening means with an adjustable limit torque.

[0018] The controller is configured to control the first and second processing devices such that the cutting insert is first held and then released or fastened. If the cutting insert is already attached to the cutting tool, the first processing device can secure the cutting insert so that the cutting insert remains in position after the fastening means is released. If the cutting insert is to be attached to the cutting tool, it must be positioned by the first processing device such that the second processing device can smoothly fasten the cutting insert using the fastening means.

[0019] Overall, the system according to the invention results in an advantageous, automated device, particularly for exchanging cutting inserts of cutting tools. The resulting advantages are particularly evident when used in environments with a large number of machine tools, as manual effort is significantly reduced while ensuring consistently high precision.

[0020] In an advantageous embodiment, the system further comprises a separate fixing device for receiving a cutting tool, to which the cutting insert can be attached for use, for inserting and removing the cutting insert when the cutting tool is arranged on the fixing device. The cutting tool can be designed to receive a plurality of cutting inserts, which are distributed approximately over a circumferential surface of the cutting tool. The cutting tool, together with the cutting inserts, could form a milling cutter that is attached to a rotating element of a machine tool, for example via a Morse taper pair. The fixing device could, for example, have a receiving device that corresponds to a receiving device of such a machine tool.The cutting tool can then be detachably attached to the fixing device to exchange the cutting inserts, so that the two processing devices then carry out the exchange on the cutting tool aligned by the fixing device. In one embodiment, the first and / or the second processing device could be designed to remove the cutting tool from the machine tool or a transport device and insert it into the fixing device. The fixing device is preferably designed to position the cutting insert or a section of the cutting tool receiving the cutting insert by moving the cutting tool such that a corresponding fastening means can be handled from a preferred direction, e.g., vertically from below or from above.If a cutting tool has multiple cutting inserts, the fixing device can be configured to align or present the individual cutting inserts one after the other, allowing the processing devices to perform an exchange. The fixing device is also preferably configured to lock the cutting tool so that the cutting tool remains in the intended location and in the intended orientation when using the two processing devices.

[0021] Furthermore, the fixing device could be arranged in an area that is located within a working area of ​​the first processing device and the second processing device. This allows both processing devices to access the cutting insert located on the cutting tool in the fixing device. The working area is understood to be a spatially defined space in which parts of the respective processing device can move.

[0022] As explained above, the gripping element can comprise a suction gripper or a clamping gripper. The suction gripper can, in particular, comprise a suction cup that can be coupled to a vacuum line via a valve. Opening the valve creates a vacuum at the suction cup, so that when the suction cup is located on or at the cutting insert, the suction cup holds the cutting insert. A clamping gripper can comprise several members that can be moved relative to one another and with which the cutting insert can be clamped.

[0023] According to the invention, the system comprises a storage device with a plurality of receptacles for temporarily storing cutting inserts, wherein the storage device is designed to insert cutting inserts into and remove them from the at least one receptacle, wherein a cutting insert can be inserted into each receptacle. The storage device can be placed near the first processing device to enable the first processing device to remove cutting inserts from or insert them into the storage device. The storage device can be manually and / or automatically loaded with cutting inserts and allows for automated replacement. The storage device can be individually tailored to the respective cutting inserts to ensure damage-free, safe storage.

[0024] According to the invention, the receptacles each comprise a centering device that is shaped complementarily to the cutting insert and is designed to hold the cutting insert in a predetermined orientation. Each cutting insert that is placed in the receptacle can then be given the predetermined orientation. If the cutting insert is removed from the receptacle, the first processing device is thus able to guide the cutting insert with the predetermined orientation to the cutting tool without prior checking of the orientation. Alignment with the centering device can therefore improve the handling of the cutting insert and its correct alignment on the cutting tool. It is of course possible to provide a storage device that has different receptacles with different centering devices for different cutting inserts.Furthermore, several storage devices could be provided simultaneously, each having at least one such receptacle. The control system can be designed to have knowledge of the different storage devices and / or receptacles, or be capable of recognizing their characteristics in order to be able to control the first processing device accordingly. The centering device can be configured in such a way that it leads to automatic alignment of the cutting insert through surface contact with the cutting insert and utilizing gravity. This could also be used, for example, to turn an indexable insert, since the first processing device can place an indexable insert with a worn cutting edge into a receptacle so that it aligns itself accordingly and can then grip it again. This allows different access directions orAlignments of the indexable insert on the first processing device.

[0025] As an alternative to the passive centering device mentioned above, an actively controlled turning device can also be used.

[0026] The fastening tool preferably comprises a screwdriving device. This can be used to loosen or tighten a screw or a bolt as a fastening means. The screwdriving device preferably comprises a shaft with a profile which can be coupled to a screw or the like, such that a torque can be transferred from the screwdriving device to the screw. The shaft could be adapted to the installation situation of the respective cutting insert, such that the screwdriving device can be moved directly to the screw in question without touching surrounding parts. It is particularly advantageous if the second processing device is designed to check the current orientation of a screw for engagement in the profile by optical image capture and subsequent image analysis in order to precisely position the screwdriving device.The screwdriving device can have a device for picking up a screw in order to guide the screw to the cutting insert from the outside. This device could, for example, comprise a magnet. Alternatively, an additional gripping device or a vacuum device would be conceivable. The screwdriving device could be connectable to a storage device for providing screws, so that a screw can be removed from the storage device and guided to the cutting insert to secure the cutting insert.

[0027] Furthermore, it is particularly advantageous if at least one of the first processing device and the second processing device is a multi-axis robot. The processing devices can then perform a very wide range of movements and can thus be adapted to different machine tools, cutting tools, or fixing devices. The processing devices are then particularly well suited for the flexible exchange of a large number of cutting inserts on different cutting tools, since they have a large working range due to their multi-axis mobility.

[0028] At least one of the first processing device and the second processing device could be configured to carry an interchangeable handling tool. For example, the first processing device could be configured to carry different gripping elements. The second processing device could be configured to receive different fastening tools. Both processing devices could also be configured to independently pick up the respective handling tools from a series of handling tools. The controller can control the processing devices so that they pick up a handling tool suitable for the intended process.

[0029] It is particularly advantageous if the controller is designed to read in an identifier of the cutting tool when handling a cutting insert and to control at least one of the first and second processing devices in such a way that it receives a suitable handling tool. For example, each cutting insert and / or each cutting tool could be equipped with an RFID tag or a barcode that makes an identifier readable. Based on this, the controller can determine which type of cutting tool is present, which cutting inserts and which number of cutting inserts are present, as well as their arrangement on the cutting tool. The controller can then select the handling tool and position the cutting tool for loosening or tightening the screws by controlling the individual components, i.e.the processing devices and, if applicable, the fixing device, are controlled accordingly.

[0030] The invention further relates to a method for inserting or removing cutting inserts of a cutting tool according to claim 9, comprising the steps of positioning a gripping element of a first processing device on a cutting insert, holding the cutting insert by the gripping element, positioning a fastening tool of a second processing device on a fastening means holding the cutting insert, fastening or releasing the fastening means by means of the fastening tool while holding the cutting insert, and releasing the cutting insert by means of the first processing device.

[0031] In an advantageous embodiment, the method comprises the steps of removing a cutting tool carrying the cutting insert from the machine tool, inserting the cutting tool into a fixing device, and after handling the cutting insert with the cutting tool arranged in the fixing device, removing the cutting tool from the fixing device and inserting the cutting tool into the machine tool.

[0032] It is advantageous if the holding comprises applying a negative pressure to a suction gripper or moving members of a clamping gripper to clamp the cutting insert.

[0033] According to the invention, the method further comprises the step of introducing the cutting insert into a receptacle of a centering device of a bearing device, wherein the centering device is shaped complementarily to the cutting insert and is designed to hold the cutting insert in a predetermined orientation.

[0034] In addition, the fastening or detaching may comprise actuating a screw-driving device on the second processing device. SHORT DESCRIPTION OF THE CHARACTERS

[0035] Further features, advantages, and possible applications of the present invention will become apparent from the following description of the exemplary embodiments and the figures. In the figures, the same reference numerals refer to the same or similar objects. Fig. 1 bis 3 show an overview of a system for inserting or removing cutting inserts in a three-dimensional representation in different states. Fig. 4 shows a storage device with holders for holding cutting inserts. Fig. 5a und 5b show a screw turning device on a cutting insert. Fig. 6 und 7 each show a method for inserting or removing cutting inserts of a cutting tool in a block-based representation. DETAILED REPRESENTATION OF EXEMPLARY EMBODIMENTS

[0036] Fig. 1 shows a system 2 for inserting and removing cutting inserts of a cutting tool. The system 2 comprises a first processing device 4 and a second processing device 6. The processing devices 4 and 6 are designed as multi-axis robots and coupled to a controller 8, which can be implemented as a microcontroller, computer, or the like. The controller 8 could also be integrated into the respective processing device 4 or 6 itself, instead of in the form of a separate device. Furthermore, Fig. 1 A fixing device 10 is shown in which a cutting tool 12, which can hold one or more cutting inserts, can be fixed and aligned. Arranging the cutting tool 12 on the fixing device 10 enables handling of the cutting insert separately from a machine tool. The fixing device 10 is designed to specifically align the cutting tool 12 so that cutting inserts can be attached to or removed from it.

[0037] The first processing device 4 has a gripping element 14 for holding or securing a cutting insert. The second processing device 6, meanwhile, has a fastening tool 16 for fastening or releasing a fastener holding the cutting insert. The controller 8 is configured to control the first processing device 4 to hold the cutting insert and the second processing device 6, with the cutting insert held, to fasten or release the fastener. This allows a cutting insert to be exchanged using the two processing devices 4 and 6.

[0038] Multiple cutting inserts can be arranged in a storage device 18 so that they can be removed from the first processing device 4 as needed. For this purpose, the storage device 18 has several receptacles, each of which can accommodate a cutting insert. This is illustrated in a subsequent figure.

[0039] Fig. 2 shows a series of different handling tools 20, which can be used as needed on at least one of the processing devices 4 and 6 to handle different cutting inserts or cutting tools 12. For example, the first processing device 4 can accommodate different gripping elements 14 to hold different cutting inserts. The second processing device 6, meanwhile, can accommodate different fastening tools 16 to loosen or tighten different fastening means.

[0040] In Fig. 3 By way of example, a tool carrier gripping element 22 is shown on the second processing device 6, which is designed to grip the cutting tool 12 and to move it, for example, from a respective machine tool or a transport device in which several cutting tools 12 with worn or already replaced cutting inserts are arranged, into the fixing device 10 or vice versa.

[0041] Fig. 4 shows a detail of the bearing device 18. On an upper side 24, a plurality of receptacles 26 are arranged, which are designed to receive or align cutting inserts only in a specific orientation. The cutting inserts could, for example, be indexable inserts. For this purpose, the receptacles 26 each have, for example, a pin 28 surrounded by two centering flanks 30. The cutting inserts can, for example, have a central bore provided for receiving the fastening means. With this central bore, the cutting inserts are each placed on the pin 28 and aligned by surface contact with the centering flanks 30, so that they then lie flush on the upper side 24 between the centering flanks 30 in a precisely predefined orientation.The first processing device 4 can then grip a cutting insert in the specified orientation in order to then precisely position it on the cutting tool 12 or the relevant machine tool. A complex check of the current orientation of the cutting inserts after their removal from the holder 26 is therefore not necessary. Fig. 5a und 5b show a screwdriving device 32 that can be arranged on the second processing device 6. The gripping element 14 of the first processing device 4 is designed as a gripping suction cup and, in the illustration shown, is in surface contact with a cutting insert 34 to hold it using a vacuum, while the screwdriving device 32 rotates a fastener 36 to loosen or fasten the cutting insert 34.

[0042] Fig. 6 shows a first variant of a method for inserting or removing cutting inserts from a cutting tool. It begins, for example, with the pickup 38 of a cutting tool 12, for example from a transport device, and the transfer 40 to the fixing device 10. This picks up the cutting tool 12 42. At the second processing device 6, the handling tool could be changed 44, in order to then move it towards the cutting tool 12. The cutting tool 12 could be positioned 46 by the fixing device 10 in order to be able to reach the cutting insert in question easily or from the desired direction. The first processing device 4 fixes 48 a cutting insert to be replaced, for example an indexable insert 34. As in Fig. 5a As shown, the fastening means 36 can be loosened 50. The cutting tool 12 can then be repositioned 52 in order to have the indexable insert 34 transported away 54 by the first processing device 4. A new indexable insert 34 is then transported 56 and fixed 58 in order to be subsequently fastened 60. The cutting tool 12 can be oriented during loosening 50 so that the fastening means 36 is unscrewed from below, whereas during fastening 60 the screwing is carried out from above and gravity assists in positioning the indexable insert 34.

[0043] In Fig. 7 A slight variation is shown in which several cutting inserts are replaced one after the other. Thus, the cutting tool 12 is positioned several times 52 and several fasteners 36 are released one after the other 50.

[0044] Additionally, it should be noted that "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Reference signs in the claims are not to be considered limiting. REFERENCE SYMBOL

[0045] 2System 4First processing device 6Second processing device 8Control 10Fixing device 12Cutting tool 14Gripping element 16Fastening tool 18Storage device 20Handling tool 22Tool carrier gripping element 24Top 26Holder 28Pin 30Centering flank 32Screwdriving device 34Cutting insert 36Fastener 38Holder 40Transfer to fixing device 42Pick up the tool carrier 44Changing the handling tool 46Positioning the fixing device 48Fixing the processing device 50Releasing the fastener 52Positioning the tool carrier 54Removing the cutting insert 56Transporting the cutting insert 58Fixing the cutting insert 60Fastening the cutting insert

Claims

1. A system (2) for inserting or removing machining inserts (34) of a machining tool (12), comprising: - a first processing device (4), - a second processing device (6), and - a controller (8) coupled to the first processing device (4) and the second processing device (6), wherein the first processing device (4) comprises a gripping element (14) for holding or securing a machining insert (34), wherein the second processing device (6) comprises a fastening tool (16) for fastening or releasing a fastening means (36) holding the machining insert (34), and wherein the controller is configured to control the first processing device (4) for holding the machining insert (34) and to control the second processing device (6) for fastening or releasing the fastening means (36) when the machining insert (34) is held, the system (2) further comprising a storage device (18) with a plurality of receptacles (26) for temporarily storing machining inserts (34), wherein the storage device (18) is configured to insert and remove machining inserts (34) into and from the receptacles (26), wherein a respective machining insert (34) is introducible into each receptacle (26), wherein the receptacles (26) each comprise a centering device which is shaped complementary to the machining insert (34) and is configured to hold the machining insert (34) in a predetermined orientation.

2. The system (2) according to claim 1, further comprising a separate fixing device (10) for receiving a machining tool (12) to which the machining insert (34) is attachable for use, for inserting and removing the machining insert (34) when the machining tool (12) is arranged on the fixing device (10).

3. The system (2) according to claim 2, wherein the fixing device (10) is arranged in an area located in a working area of the first processing device (4) and the second processing device (6).

4. The system (2) according to any one of the preceding claims, wherein the gripping element (14) comprises a suction gripper or a clamping gripper.

5. The system (2) according to any one of the preceding claims, wherein the fastening tool (16) comprises a screw turning device.

6. The system (2) according to any one of the preceding claims, wherein at least one of the first processing device (4) and the second processing device (6) is a multi-axis robot.

7. The system (2) according to any one of the preceding claims, wherein at least one of the first processing device (4) and the second processing device (6) is configured to carry an exchangeable handling tool (20).

8. The system (2) according to claim 7, wherein the controller (8) is configured to read in an identifier of the machining tool (12) carrying the machining insert (34) when handling a machining insert (34) and to control the at least one of the first and second processing devices (4, 6) such that it receives a suitable handling tool (20).

9. A method for inserting or removing machining inserts (34) of a machining tool (12), comprising the steps of: - positioning a gripping element (14) of a first processing device on a machining insert (34), - holding the machining insert (34) by the gripping element (14), - positioning a fastening tool (16) of a second processing device (6) on a fastening means (36) holding the machining insert (34), - fastening or releasing the fastening means (36) by means of the fastening tool (16) when the machining insert is held, and - releasing the machining insert (34) by the first processing device (4), further comprising the step of introducing the machining insert (34) into a receptacle (26) of a centering device of a storage device (18), wherein the centering device is shaped complementary to the machining insert (34) and is configured to hold the machining insert (34) in a predetermined orientation.

10. The method according to claim 9, further comprising the steps of: - removing a machining tool (12) carrying the machining insert (34) from the machine tool or a transport device, - introducing the machining tool (12) into a fixing device (10), and - after handling the machining insert (34) when the machining tool (12) is arranged in the fixing device (10), removing the machining tool (12) from the fixing device (10), and - inserting the machining tool (12) into the machine tool or the transport device.

11. The method according to claim 9 or 10, wherein the holding comprises applying a negative pressure to a suction gripper or moving members of a clamping gripper for clamping the machining insert (34).

12. The method according to any one of claims 10 to 12, wherein the fastening or releasing comprises actuating a screw turning device (32) on the second processing device (6).