Component for a Machine Tool, Machine Tool, and Method for Identifying Wear

Abstract

The present disclosure relates to a component for a machine tool, having a component main body and having at least two layers arranged thereon for identifying wear, wherein the layers for identifying wear are applied to a wear region of a component of the machine tool and wherein at least one of the two layers is a signaling layer for indicating the wear.

Claims

1. A component (100, 400) for a machine tool, having a component main body (110) and having at least two layers (120, 130; 440, 450) arranged thereon for identifying wear, wherein the layers (120, 130; 440, 450) for identifying wear are applied to a wear region of a component (100, 400) of the machine tool and wherein at least one of the two layers (120, 130; 440, 450) is a signalling layer (120) for indicating the wear.

2. The component (100, 400) for a machine tool according to claim 1, characterised in that the at least two layers (120, 130; 440, 450) are arranged alternately as a consumable layer (130) and as a signalling layer (120).

3. The component (100, 400) for a machine tool according to claim 1, characterised in that each consumable layer (130) in the initial state is arranged relatively outside with respect to the component main body (110) and each signalling layer (120) is arranged relatively between the consumable layer (130) and the component main body (110) and/or a further pair of layers made up of a consumable layer (130) and a signalling layer (120).

4. The component (100, 400) for a machine tool according to any one of the preceding claims, characterised in that the component (100, 400) is a tool (400), a machine table and/or a stop element.

5. The component (100, 400) for a machine tool according to any one of the preceding claims, characterised in that the component (100, 400) is a wear part of a bending machine, in particular a tool (400), a machine table and/or a stop element.

6. The component (100, 400) for a machine tool according to any one of the preceding claims, characterised in that the signalling layer (120) has a material with a low coefficient of friction.

7. The component (100, 400) for a machine tool according to any one of the preceding claims, characterised in that the signalling layer (120) is colour-coded and differs in colour from the consumable layer(s) (130) and/or the component main body (110).

8. The component (100, 400) for a machine tool according to any one of the preceding claims, characterised in that one of the two layers (450) has electrically conductive material and in that the other of the two layers (440) has electrically insulating material for insulating the electrically conductive material.

9. The component (100, 400) for a machine tool according to claim 8, characterised in that a transponder (470) is provided which is designed to output a signal if one of the two layers (120, 130; 440, 450) is damaged.

10. A machine tool designed for machining workpieces (400) using tools (400) having at least one component (100, 400) according to any one of claims 1 to 9.

11. The machine tool according to claim 10 having at least one component (100, 400) according to any one of claim 8 or 9, characterised in that a circuit (410) is set up on the component (100, 400), wherein the electrically conductive material functions as a switch.

12. The machine tool according to claim 11, characterised in that a control Is provided which is connected to the circuit (410), and in that the control is designed to incorporate the wear determined on the basis of the circuit (410) in the control of the machine tool.

13. The machine tool according to claim 11 or 12, characterised in that a plurality of layers (120, 130; 440, 450) are provided and in that each of the electrically conductive layers (450) is connected to a circuit (410) by means of electrically conductive material.

14. A method for identifying wear of a component (100, 400) of a machine tool according to any one of claims 10 to 12, having the steps of: checking the circuit (410) with the electrically conductive material of the layer (450) for interruption; detecting an interruption; if an interruption is detected, storing the interruption and/or adapting the control of the machine tool as a function of the wear determined on the basis of the interruption in the circuit (410).

15. The method according to claim 14, characterised in that an interruption is detected continuously, wherein an electrically conductive workpiece (400) closes the circuit (410).

16. The method for identifying wear according to claim 14, characterised in that an interruption is detected by bringing the component (100, 400) into contact with an electrically conductive part of the machine tool in order to close the circuit (410).

17. The method for identifying wear according to any one of claims 14 to 16, characterised in that, when a wear is determined which indicates the end of the maximum possible usage time of the component (100, 400), an automated spare parts order is triggered.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0036] The invention will be explained below in exemplary embodiments with reference to the accompanying drawings. In the figures:

[0037] FIG. 1 shows a schematic front view and top view of a component with optical wear identification;

[0038] FIG. 2 shows a schematic front view and top view of a worn component with optical wear identification;

[0039] FIG. 3 shows a perspective view of a bending machine with a component with wear identification as a stop finger;

[0040] FIG. 4 shows a schematic representation of a component with electrical wear identification;

[0041] FIG. 5 shows a perspective view of a bending machine with a punch and die;

[0042] FIG. 6 shows a schematic representation of a die with electrical wear identification; and

[0043] FIG. 7 shows a schematic representation of the punch with electrical wear identification.

DETAILED DESCRIPTION OF THE INVENTION

[0044] As used throughout the present disclosure, unless specifically stated otherwise, the term “or” encompasses all possible combinations, except where infeasible. For example, the expression “A or B” shall mean A alone, B alone, or A and B together. If it is stated that a component includes “A, B, or C”, then, unless specifically stated otherwise or infeasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. Expressions such as “at least one of” do not necessarily modify an entirety of the following list and do not necessarily modify each member of the list, such that “at least one of “A, B, and C” should be understood as including only one of A, only one of B, only one of C, or any combination of A, B, and C.

[0045] FIG. 1 shows a schematic front view and top view of a component 100 with a component core or component main body 110 and optical wear identification 120, 130 applied thereon. The component 100 can be a wear part of a bending machine, in particular a tool, a machine table and/or a stop element such as a stop finger. Correspondingly, the wear part of a bending machine can comprise a main body 110 with optical wear identification 120, 130 attached thereon.

[0046] The component 100 is provided with an outer hard material layer or consumable layer 130 according to the intended use. Possible materials here are, for example, PVD and/or CVD hard material layers or materials such as titanium nitride. The layer thickness is selected with regard to the application and the expected component wear. The layer thickness is advantageously 1 to 10 micrometers and particularly advantageously 1 to 20 micrometers. In addition, greater layer thicknesses can also be used. The layer thickness depends on the application method and the subsequent adhesion to the component 100 or the layer below.

[0047] It does not matter whether the layer has conductive or insulating properties. A further layer, a signaling layer 120, was applied below the outer consumable layer 130 during component manufacture. This signaling layer 120 is clearly distinguishable in color from the consumable layer 130 and is advantageously applied in a signal color.

[0048] Various colors are possible, such as gold, blue-grey, red-brown, grey, pearl pink, pink, etc. It is particularly important to distinguish between the layers. The color results from the applied material, e.g., TiN is golden yellow, and/or from variations in the application technology. The entire layer accordingly consists of a colored material, i.e., as long as parts of the layer are still present, the color can still be clearly recognized.

[0049] This inner signaling layer 120, like the consumable layer 130, can have wear-minimizing properties. For example, titanium nitride is a common all-round wear coating. Layers made of titanium carbonitride or titanium chromium nitride are also conceivable. The signaling layer 120 is applied to a component main body 110 of the component 100. The signaling layer 120 and also the consumable layer 130 can be applied specifically in a wear region of the component 100, such as a surface, edge, three-dimensional region, etc. Likewise, the layers 120 and 130 can completely cover the component 100 as shown.

[0050] FIG. 2 shows a schematic front view and top view of a worn component 100 with optical wear identification.

[0051] When the component 100 is used, the outer consumable layer 130 is continuously removed by contact with the workpiece. This creates a region 130a in which the outer consumable layer 130 is partially removed, i.e., worn. As already described, the geometry of the component 100 changes, the component 100 wears. After the outer consumable layer 130 has been completely removed, the inner, i.e., the underlying signaling layer 120 is visible (which differs both from the color of the consumable layer 130 and from the intrinsic color of the component main body 110) and is clearly displayed to the operator by the signal color. This gives the operating personnel a clear indication that the wear limit has been reached, the quality of the products is declining, and the replacement of the component is imminent.

[0052] In the optimal case, after the consumable layer 130 has been completely removed, i.e., the signaling layer 120 underneath has been exposed, there is enough time to replace the parts before the component 100 fails. The remaining time can be defined via the thickness of the outer consumable layer 130. Various layers with correspondingly assigned colors can be used to provide a quantitative statement of the degree of wear. The degree of wear can thus be displayed to the user and further steps can be initiated. One possible color variant would be, for example, the use of the traffic light colors green, yellow, red. The currently translucent color can be transmitted to the machine control in order to adjust the infeed of the machine axes according to the degree of wear. In this example, the consumable layer 130 could have the color green, the signaling layer 120 would have the color yellow and the component main body 110 would have the color red. Alternatively, only the signaling layer 120 might have a color, for example red.

[0053] FIG. 3 shows a perspective view of a bending machine 300 with a component with wear identification as a stop finger 310. Stop fingers 310 of bending machines 300 enable correct leg lengths of the bent parts by striking and positioning the sheet metal relative to the bending line. The finger contours optimized for this are subject to high wear due to sheet positioning and pivoting during the bending process. As a result, the bent parts can then no longer be correctly positioned. Methods of heat treatment of the stop fingers 310 are already known to minimize wear. Subsequently, the components are coated with physical and/or chemical vapor deposition, for example.

[0054] FIG. 4 shows a schematic representation of a component 400, for example a stop finger, with electrical wear identification. For this purpose, the component 400 is connected to an electrical circuit 410 or is part of the electrical circuit 410. The electrical circuit 410 comprises a supplier such as a voltage source and a consumer 430 at which electrical parameters such as voltage or current can be measured. The component 400 then functions as a switch. In other words, the component 400 is sometimes a conductor and sometimes an insulator. A suitable consumer 430 monitors and displays whether the circuit 410 is closed.

[0055] The component 400 is provided with a plurality of alternating insulating layers 440 and electrically conductive layers 450 during manufacture. The electrically conductive layers 450 have electrically conductive material or consist entirely of this material. These layers 440, 450 are configured to be application-related and, in addition to minimizing wear, can also be provided with sliding properties. Most DLC coatings (diamond-like carbon) achieve good sliding properties, but PVD coatings (physical vapor deposition) are also advantageous compared to untreated or only heat-treated materials. The layer thickness is precisely determined by the manufacturing process of the component 400. At least one electrically conductive layer and one insulating layer must be present. The order the layers 440, 450 are applied is irrelevant here. The thicknesses of the applied layers 440, 450 can vary, a thickness in the absolute value of the tolerated wear is advantageous. The respective thicknesses must be known and stored in a control, for example in the machine control. With the exception of a connection point 460, the finger is insulated on all sides and is therefore no longer electrically conductive.

[0056] When installed, an electrical voltage is applied to the machine, for example with the anode on the conductive point of the finger and the cathode on the machine table or the die. The positioning of bent parts—predominantly made of conductive materials—in the bending process does not lead to a closed circuit, as the insulating hard material layer of the finger is still completely intact. Increasing wear on the finger removes the insulating layer 440 until the circuit 410 is closed. Using suitable evaluation mechanisms—normally the machine control—the contact is established and measures are taken. Ideally, the tolerated deviation has now been reached and the finger would have to be swapped.

[0057] A wearing component 400 will alternately open and close the circuit 410. The number of these processes and the layer thickness value allow an exact conclusion about the degree of wear of the component 400 and are stored and further processed in the machine control. The constantly changing geometry of the component 400 can be included in the production process and the affected machine axis can be adjusted in advance. The affected machine axis is then always readjusted by the amount of the worn layer.

[0058] The checking of the components 400 can take place continuously in the bending process or as initialization. During the bending process, the electrically conductive workpiece 400 is used as a component of the circuit 410 and is included in the test. The layer thicknesses can then be determined in the entire bending process.

[0059] An initialization phase requires a recurring connection with a conductive, stationary material on the machine. The component 400 to be checked for wear is then positioned with the machine axis at a specified point within the machine. According to the invention, this intermediate element is an electrically conductive brush. The avoidance of an undesired collision (contact region) and the covering of a large inspection region (no line contact) are advantageous here. A line contact or sometimes a point contact may be desired. Although the brush enables a 3D contour to be scanned, this can complicate the detection as the component is worn. To simplify this process, it can be advantageous to monitor a point or a line—either exclusively or in addition.

[0060] The principle of identifying wear through conductivity is in principle not limited to electrical conductivity. Alternatively, conductivity for electromagnetic waves, for example light, or magnetic flux could also be used. Such embodiments are also considered to be according to the invention.

[0061] An exemplary sequence is shown below.

[0062] During an initial test of the component 400, the circuit 410 is closed. If the outer insulating layer 440 is still intact, there is no signal at the consumer 430. There is no message to the machine control.

[0063] After working with the component, i.e., contact with the workpiece, the component 400 is tested, and the circuit 410 is closed. If the outer insulating layer 440 is still intact, there is no signal at the consumer 430. There is no message to the machine control.

[0064] After working further with the component, i.e., contact with the workpiece, the component 400 is tested, and the circuit 410 is closed. The outer insulating layer 440 is now no longer intact, the conductive layer 450 is on the outside, and there is a signal at the consumer 430. A message is therefore sent to the machine control. The new component geometry is offset in the form of a subtraction of the amount of the outermost layer 440 and a recalibration of the relevant machine axis or machine axes.

[0065] After working further with the component, i.e., contact with the workpiece, the component 400 is tested, and the circuit 410 is closed. The conductive layer 450 is still intact, there is a signal to the consumer 430. There is no message to the machine control.

[0066] After working further with the component, i.e., contact with the workpiece, the component 400 is tested, and the circuit 410 is closed. The conductive layer 450 is now no longer intact, the next insulating layer is on the outside, and consequently there is no signal at the consumer 430. A message is therefore sent to the machine control. The new component geometry is offset in the form of a subtraction of the amount of the conductive layer 450 and a recalibration of the relevant machine axis or machine axes.

[0067] This procedure is continued until the last layer is reached or until the component 400 is replaced as part of maintenance.

[0068] The absolute frequency of the measurements depends on various factors and is variable. The conductive layers 450 can each be checked with their own circuit, then a more precise localization of the interruption (damaged region) and thus a more differentiated statement of wear is possible. A further improvement is created by a two- or three-dimensional layer structure. Complex geometries can thus be monitored.

[0069] The component 400 is also equipped with a transponder 470, which is designed to output a signal if one of the two layers 440, 450 is damaged.

[0070] The determined signs of wear can now be clearly assigned to a replaceable component 400. Such components on press bakes are mainly bending tools, i.e., punches and dies. Bending tools can be freely combined with one another and are product specific. A constant change of these components is typical. It is therefore necessary to differentiate between these components.

[0071] A clear assignment of the degree of wear can advantageously be achieved with an RFID system. The RFID transponder 470 is attached to the tool 400 and identifies the same. The transponder 470 is coupled to the layer structure described and sends a signal whenever a layer has been damaged. The machine control can also correct the feed rate in accordance with the changed geometry. Suggestions for an advantageous division of the components are also conceivable: Evenly worn components are preferably grouped together. The tools can also be clearly assigned using a code (QR code, barcode, 2D code, numeric input, etc.). The code is read out appropriately and the data is transferred to the machine control system or entered by the operator.

[0072] FIG. 5 shows a perspective view of a machine tool in the form of a bending machine 500 having die 510 and punch 520. The two components in the form of the die 510 and the punch 520 are provided with wear identification or wear monitoring as described above.

[0073] FIG. 6 shows a schematic representation of the die 510 with electrical wear identification. The die 510 is connected to an electrical circuit 410 or is part of the electrical circuit 410. The electrical circuit 400 comprises a supplier such as a voltage source and a consumer 430 at which electrical parameters such as voltage or current can be measured. The die 510 then functions as a switch. In other words, the die 510 is sometimes a conductor and sometimes an insulator. A suitable consumer 430 monitors and displays whether the circuit 410 is closed.

[0074] The die 510 is provided with a plurality of alternating insulating layers 440 and conductive layers 450 during manufacture. The conductive layers 450 have electrically conductive material or consist entirely of this material. These layers 440, 450 are configured to be application-related and, in addition to minimizing wear, can also be provided with sliding properties. The layer thickness is precisely determined by the manufacturing process of the die 510. At least one conductive layer and one insulating layer must be present. The order in which the layers 440, 450 are applied is irrelevant here. The thicknesses of the applied layers 440, 450 can vary, a thickness in the absolute value of the tolerated wear is advantageous. With the exception of a connection point 460, the die 510 is insulated on all sides and is therefore no longer electrically conductive. A transponder 470 for identifying the die 510 and for reporting the state of wear or a layer change is provided on the die 510.

[0075] When the machine tool is in operation, the die 510 can be used analogously to the description above.

[0076] FIG. 7 shows a schematic representation of the punch 520 with electrical wear identification. The punch 520 is connected to an electrical circuit 410 or is part of the electrical circuit 410. The electrical circuit 400 comprises a supplier such as a voltage source and a consumer 430 at which electrical parameters such as voltage or current can be measured. The punch 520 then functions as a switch. In other words, the punch 520 is sometimes a conductor and sometimes an insulator. A suitable consumer 430 monitors and displays whether the circuit 410 is closed.

[0077] The punch 520 is provided with a plurality of alternating insulating layers 440 and conductive layers 450 during manufacture. The conductive layers 450 have electrically conductive material or consist entirely of this material. These layers 440, 450 are configured to be application-related and, in addition to minimizing wear, can also be provided with sliding properties. The layer thickness is precisely determined by the manufacturing process of the punch 520. At least one conductive layer and one insulating layer must be present. The order in which the layers 440, 450 are applied is irrelevant here. The thicknesses of the applied layers 440, 450 can vary, a thickness in the absolute value of the tolerated wear is advantageous. With the exception of a connection point 460, the punch 520 is insulated on all sides and is therefore no longer electrically conductive. A transponder 470 for identifying the punch 520 and for reporting the state of wear or a layer change is provided on the punch 520.

[0078] When the machine tool is in operation, the punch 520 can be used analogously to the description above.

[0079] The die 510 and the punch 520 are each shown with a separate circuit 410. Another possibility is to use a common circuit which is then closed by an electrically conductive workpiece located between the die 510 and the punch 520.

[0080] The wear identification presented here allows simple and precise detection of the respective wear state of one or more components of a machine tool, so that the machine control can be adapted, and corresponding maintenance processes can be initiated.

[0081] In addition, the machine control system can trigger an automated order for spare parts if wear is determined that indicates the end of the maximum possible usage time of the component. As a result, the replacement component can already be available when the end of the maximum usage time of the component is reached.