Method for producing uniform workpieces

Abstract

The invention relates to a method for machining at least one first workpiece (5A) by means of a first tool (3A) having a first tool effective radius (RA) and a second workpiece (5B) by means of a second tool (3B) having a second tool effective radius (RB), wherein a target contour (S) for the workpieces (5A, 5B) is specified, wherein a first tool path (TA) for the first tool (3A) is determined on the basis of the first tool effective radius (RA), wherein on account of a curve, a corner or an edge in the target contour (S), the target contour (S) cannot be produced without error using the first tool (3A) because of the first tool effective radius (RA), but only in the form of a first actual contour (IA), which comprises a first deviation contour (AA) compared to the target contour (S) in the region of the curve, the corner or the edge. The aim of the invention is to produce largely identical workpieces with different tools that differ in terms of their tool effective radius. For this purpose, according to the invention, a new target contour (NS) is produced which comprises the deviation contour (AA), wherein a new second tool path (TB') for the second tool (3B) is determined on the basis of the second tool effective radius (RB) in order to produce the new target contour (NS), wherein the first workpiece (3A) is machined according to the first tool path (TA) and the second workpiece (3B) is machined according to the new second tool path (TB').

Description

[0001] 202414254 Foreign version Fair copy

[0002] 1

[0003] Description

[0004] Methods for producing uniform workpieces

[0005] The invention relates to a method for machining at least one first workpiece using a first tool with a first tool radius and a second workpiece using a second tool with a second tool radius, wherein a target contour for the workpieces is specified, wherein a first toolpath for the first tool is determined as a function of the first tool radius, wherein, due to a curvature, a corner or an edge in the target contour, the target contour cannot be produced flawlessly with the first tool due to the first tool radius, but only in the form of a first actual contour, which in the area of ​​the curvature, the corner or the edge includes a first deviation contour from the target contour, wherein a new target contour is produced which includes the deviation contour.

[0006] Furthermore, the invention relates to a control device for carrying out such a method.

[0007] Furthermore, the invention relates to a machine tool system comprising at least one control device and one machine tool.

[0008] When machining workpieces using machine tools, the problem arises that, due to the not arbitrarily small dimensions of the tool used, certain contours of the workpiece cannot be produced exactly, especially edges or particularly strong curvatures when machining the workpiece using a milling cutter with a specific tool radius.

[0009] Such machining operations inevitably result in deviations between a desired target contour and a realizable actual contour. For example, a sharp edge or corner can only be milled as a rounded section whose radius of curvature is equal to or greater than the tool radius.

[0010] When using different tools, e.g. a new tool and a used, already worn tool with the same standard dimensions, it is common practice with known control devices, especially CNC controls, to use the actual 202414254 Foreign version Fair copy

[0011] 2

[0012] The tool radius must be taken into account, and toolpaths for machining the workpiece must be determined based on the current tool radius. This tool radius correction by the control unit results in workpieces machined with different tools differing, particularly in the area of ​​edges or highly curved surfaces. Often, the problem is not the deviations between the target contour and the actual contour per se, but rather the deviations between the manufactured workpieces themselves.

[0013] From the publication: SIEMENS AG "SINUMERIK 840D sl Tools", PRIOR ART PUBLISHING GMBH, MANFRED-VON-RICHTHOFEN-STR. 9, 12101 BERLIN GERMANY, Vol. www.priorartregister.com, December 16, 2020 (2020-12-16), pages 1-330, XP007023717, a CNC control for machine tools is known which is also suitable for controlling multi-spindle machine tools. The document discloses in section 4.1.2.3 the behavior at inside corners, in sections 4.1.2.4 and 4.1.3.7 the monitoring of path curvature, and in section 4.3.3 the 3D peripheral milling taking into account a boundary surface (CUT3DCC, CUT3DCCD).

[0014] German patent application DE10341776A1 discloses a method for machining a workpiece using a rotating, cutting tool, wherein the tool is moved along paths relative to the workpiece. At least one tool defines the edges of an area to be machined, and a positioning and / or lifting movement of the tool is defined within the area of ​​the edges of the areas to be machined. This positioning and / or lifting movement is carried out by the tool during machining of the workpiece within the area of ​​the edges of the areas to be machined.

[0015] The object of the invention is to produce at least largely identical workpieces despite the use of different tools.

[0016] This problem is solved according to the invention by a method with the features according to claim 1, i.e., a method for machining at least one first workpiece by means of a first tool with a first tool effective radius and a second workpiece by means of a second tool with a second tool effective radius, wherein a target contour for the workpieces is specified, 202414254 Foreign version Fair copy

[0017] 3 wherein a first toolpath for the first tool is determined depending on the first tool effective radius, wherein due to a curvature or an edge in the target contour the target contour cannot be produced without errors with the first tool due to the first tool effective radius, but only in the form of a first actual contour which in the area of ​​the curvature or the edge includes a first deviation contour compared to the target contour, wherein a new target contour is generated which includes the deviation contour, wherein a new second toolpath for the second tool is determined depending on the second tool effective radius to generate the new target contour, wherein the first workpiece is machined according to the first toolpath and the second workpiece according to the new second toolpath.

[0018] Furthermore, the problem is solved by a control device according to claim 7, i.e., a control device for a machine tool for machining at least one first workpiece by means of a first tool with a first tool effective radius and a second workpiece by means of a second tool with a second tool effective radius, in particular for carrying out a method according to one of claims 1 to 7, wherein a target contour for the workpieces can be specified, wherein a first toolpath for the first tool can be determined as a function of the first tool effective radius by means of the control device and a correction device comprised therein, wherein, due to a curvature or an edge in the first target contour, the first target contour cannot be produced without errors with the first tool due to the first tool effective radius, but only in the form of a first actual contour.which in the area of ​​the curvature or the edge includes a first deviation contour from the first target contour, wherein a new target contour can be generated which includes the deviation contour, wherein a new second toolpath for the second tool can be determined depending on the second tool effective radius to generate the new target contour, wherein the first workpiece can be machined according to the first toolpath and the second workpiece according to the new second toolpath.

[0019] Furthermore, the problem is solved by a machine tool system according to claim 13 and a digital twin of a machine tool system according to claim 15. 202414254 Foreign version Fair copy

[0020] 4

[0021] Advantageous embodiments of the invention are characterized by the dependent patent claims.

[0022] The invention can generally be applied to a wide variety of different machine tools or different types of machine tools. It is particularly advantageous for use with CNC-controlled milling machines.

[0023] In the field of machine tools, some machines are designed as multi-spindle machine tools, also known as multi-spindle machines. These have two or more tool spindles for machining two or more workpieces. This means that two or more machining operations, and therefore the motion control and spindle control, must be performed simultaneously, i.e., synchronously. The application of multiple synchronous machining units on one machine can be applied to a wide variety of technologies, for example, milling, turning, grinding, and so on. Multi-spindle machine tools with exactly two tool spindles are also called twin-spindle machine tools or twin-spindle machines.

[0024] Twin-spindle machines, for example, can machine two workpieces simultaneously with two tools, resulting in two nominally identical workpieces at the end of the machining process. The machining of both workpieces is synchronous. This means that the output on a twin-spindle machine is twice as high compared to a single-spindle machine. However, a twin-spindle machine can also be operated to produce only one workpiece; in this case, the second spindle is inactive.

[0025] There are various concepts for twin-spindle machining centers, the complexity of which can be tailored to specific production and accuracy requirements. These concepts differ in their design, for example, in the degrees of freedom of the individual tool spindles or machining units.

[0026] In simple twin-spindle machines, the two tool spindles are rigidly connected mechanically. The spindle assembly is then moved by the common axes, for example, the X, Y, and Z axes. This simple concept, therefore, can only account for tool wear on one side. Ideally, identical tools or tools with identical wear must be used to produce identical workpieces during manufacturing. 202414254 Foreign version Fair copy

[0027] 5

[0028] A more complex concept provides independent Z-axes for each of the two tool spindles. This allows the tool spindles to be positioned differently in the Z-direction. An even more complex concept, through the use of compensating axes redundantly mounted on the main axes, enables the tool spindles, and thus the tools, to be moved in all three axis directions, albeit only for comparatively short travel ranges. This type of twin-spindle machine is at least capable, compared to the previously described concepts, of handling completely different tool corrections and, if necessary, workpiece clamping situations.

[0029] Particularly high accuracy can be achieved with so-called true multi-spindle machine tools, meaning multi-spindle machine tools with two or more independent tool spindles that can be controlled and moved independently of each other. The two tool spindles of a twin-spindle machine are then, for example, each equipped with their own X, Y, and Z axes. Depending on the design and technology, additional linear and / or rotary axes (also known as rotary axes) may be provided on the multi-spindle machine tool. These can be independent for each tool spindle or cause the same (relative) movement for all tool spindles.

[0030] The tool spindles are then operated and controlled, for example, via one and the same CNC control system, each with its own machining channel, hereinafter also referred to simply as a "channel". The individual axes of the tool spindles can partially share the same guide rail.

[0031] One advantage of true multi-spindle machine tools is that the various tool spindles can be equipped with tools for manufacturing nominally identical workpieces. These tools may also be nominally identical, but their dimensions may differ, for example, due to varying wear. The independent control of the different tool spindles can compensate for these dimensional differences.

[0032] For optimal utilization of the shared workspace and a compact machine tool design, it is desirable to minimize the mechanical offset between the two tool spindles, for example, less than 1 m or in the range of 500 mm. To achieve such small distances mechanically, the movable columns on which the 202414254 Foreign Version Fair Copy

[0033] 6

[0034] Tool spindles or other moving components are mounted close together, for example, just a few millimeters apart. This creates a potential risk of collision. This risk is particularly high if the tool spindles are controlled differently to compensate for different tool dimensions, as explained above.

[0035] The invention provides that, by means of the desired target contour in conjunction with a specific tool working radius, in particular the (standard) tool working radius of a standard tool, a new target contour is determined taking the tool working radius into account. In the new target contour, edges, corners, or strongly curved surface areas are modified such that they only include curvatures whose radius of curvature is equal to or greater than the tool working radius. The new target contour can therefore always be produced flawlessly—that is, without errors caused or resulting from the tool working radius—using tools whose tool working radius is smaller than the tool working radius of the standard tool.

[0036] Therefore, the same new target contour is always generated for all workpieces, regardless of the tool used, as long as the tool radius of the tool used does not exceed the tool radius of the standard tool. This results in uniform, or at least largely identical, workpieces.

[0037] The invention is particularly advantageous for use in multi-spindle machine tools, as it contributes to the synchronization of the individual machine units, but is not limited to these.

[0038] The invention is not limited to the use of milling tools. For example, turning tools used to machine a workpiece have a tool radius at the tip of the tool. This means that edges cannot be turned with arbitrary precision. Rather, they will always have a rounded edge whose radius cannot be smaller than the radius of the turning tool at the tool tip. According to the invention, corners that are technically impossible to achieve precisely can also be defined as rounded edges.

[0039] The invention provides to determine a deviation contour starting from the target contour in the area of ​​the edge or strong curvature, which is characterized in particular by a curvature whose radius of curvature corresponds to the radius of curvature of the first tool, in particular the (standard) tool working radius of a tool considered as a reference tool.

[0040] 7

[0041] The deviation contour can therefore be generated by all (identical) tools whose tool radius is equal to or smaller than that of the standard tool, without any deviation inherent in the tool's working radius.

[0042] Advantageously, an existing part program is modified by the control unit in such a way that the new, modified part program includes instruction sets for generating the deviation contour. In particular, the new part program differs from the original in that it includes at least one, and preferably exactly one, instruction set that describes or represents the deviation contour, or whose execution generates the deviation contour.

[0043] The invention has been described for exactly one edge or exactly one curve. Naturally, the invention can be applied analogously to contours that include several such edges or curves.

[0044] Furthermore, the invention is not limited to machining a workpiece with milling cutters or turning tools, where the tool's effective radius is usually referred to as the tool radius. The invention can also be applied analogously, for example, to machining the workpiece by cutting or grinding along a desired contour.

[0045] Especially when cutting workpieces, such as with laser or waterjet cutting, it is not a specific radius (or diameter) of the tool (beam head) that is crucial, but rather the radius (or diameter) of the beam it generates at the workpiece surface. Therefore, the more general term "tool effective radius" (instead of tool radius) is used in this description, as it also includes these tools. For tools used in the machining of a workpiece, the "tool effective radius" is therefore identical to the term or specified tool radius normally used for such tools.

[0046] In this way, even when machining a workpiece by cutting, the path for a standard radius can be determined and the new target contour thus generated can also be authoritative for cutting operations with a beam radius that deviates from the standard radius.

[0047] Here too, the invention is particularly advantageous for machine tools with several, especially independently controllable, tool holders, as illustrated in 202414254 Foreign version Fair copy

[0048] 8 that allow several workpieces to be cut simultaneously and, in particular, synchronously (i.e., through identical relative movements between tool and workpiece).

[0049] The method according to the invention is carried out in particular by a computer program installed on the control device.

[0050] Advantageously, the inventive procedure can be simulated using a digital twin of the relevant machine tool.

[0051] The invention is described and explained in more detail below using exemplary embodiments. These include:

[0052] FIG 1 a multi-spindle machine tool,

[0053] FIG 2 the machining of a sharp corner,

[0054] FIG 3 the machining of a sharp corner according to the invention,

[0055] FIG 4 the machining of a blunt corner,

[0056] FIG 5 Process steps in carrying out a method according to the invention. FIG 1 schematically shows an exemplary embodiment of a multi-spindle machine tool system 1 according to the invention. This comprises a multi-spindle machine tool 2, which in the example of FIG 1 is specifically designed as a twin-spindle machine tool 2 with the two machine units MA and MB. However, the embodiments can also be applied analogously to machine tools with more than two tool spindles or machine units.

[0057] The first machine unit MA of the multi-spindle machine tool 2 has a first tool spindle 2A, which is equipped with a first tool 3A. The second machine unit MB of the multi-spindle machine tool 2 has a second tool spindle 2B, which is equipped with a second tool 3B. The second tool spindle 2B can be controlled independently of the first tool spindle 2A. In a non-restrictive example, the first tool spindle 2A and the second tool spindle 2B are each located along parallel X-axes X1, X2, parallel Y-axes Y1, Y2, and parallel Z-axes Z1, Z2 as the respective first machine axes X1, Y1, Z1 and second machine axes, respectively. 202414254 Foreign version Fair copy

[0058] 9

[0059] Machine axes X2, Y2, Z2 are movable. The X-axes are perpendicular to the Y-axes, and the Z-axes are perpendicular to both the X-axes and the Y-axes. However, other translational machine axes are also possible.

[0060] Furthermore, the multi-spindle machine tool 2, according to the exemplary embodiment, comprises a workpiece table 6 which is pivotable about an A-axis. The workpiece table 6 also includes two rotary tables 6A and 6B, on each of which a workpiece (not shown in FIG. 1) can be rotatably mounted about an axis B1 or B2, respectively. The first rotary table 6A is assigned to the first machine unit MA, and the second rotary table 6B is assigned to the second machine unit MB. The A-axis acts on both rotary tables 6A and 6B equally and is assigned to both machine units MA and MB.

[0061] The multi-spindle machine tool 2 is connected to a control unit 4, in particular a CNC control 4, for the (CNC) control of the linear axes X1, Y1 and Z1 and thus the first tool spindle 2A, the linear axes X2, Y2 and Z2 and thus the second tool spindle 2B, as well as the rotary axes A, B1 and B2. The programming of the machine axes is carried out in particular with respect to a machine coordinate system (MCS) fixed to a machine base.

[0062] By means of the multi-spindle machine tool system 1 according to the invention, a method according to the invention for CNC control of a multi-spindle machine tool 2 can in particular be carried out. For machining a first workpiece 5A (see FIG. 2) using the first tool 3A, the CNC control 4 executes a predetermined part program in a first machining channel (channel 1 or channel KA, not shown) and for machining a second workpiece 5B using the second tool 3B, the control unit 4 executes the same part program in a second machining channel (channel 2 or channel KB, also not shown) synchronously with the processing in the first machining channel.

[0063] In this process, the CNC control 4 controls the first machine axes X1, Y1, Z1 and B1 to guide the first tool 3A relative to a first workpiece (not shown in FIG. 1) according to a first toolpath in the first machining channel KA for processing the part program, and controls the second machine axes X2, Y2, Z2 and B2 to guide the second tool 3B relative to a second workpiece (not shown in FIG. 1) according to a second toolpath in the second machining channel KB for processing the part program, whereby a machining result of the first workpiece is displayed. 202414254 Foreign version Fair copy

[0064] 10 at one end of the first toolpath is equal to a machining result of the second workpiece at one end of the second toolpath.

[0065] In the embodiment shown in FIG. 2, identical workpieces 5A and 5B are to be manufactured in the two machine units MA and MB of the twin-spindle machine tool 2, with reference to the machine tool system 1 shown in FIG. 1. Workpiece 5A is manufactured in machine unit MA and workpiece 5B in machine unit MB. Machine unit MA is equipped with the first milling tool 3A, which, in this embodiment, has the standard tool working radius RA. This allows, in principle, the production of contours without contour defects, which have no internal edges and where curvatures always have a radius of curvature greater than the tool working radius RA.

[0066] Both workpieces 5A and 5B are to have a sharp corner milled as shown. The same part program (G-code program) is executed in the two channels KA and KB of the CNC control 4 to control the two machine units MA and MB, in particular the two spindles 2A and 2B.

[0067] For example, the parts program in channels KA (channel 1) and KB (channel 2) could be as follows:

[0068] Tool “Spindle 1” Channel 1: Tool “Spindle 2” Channel 2:

[0069] L=100 L=100

[0070] R=5 R=4.5

[0071] Parts program for both channels:

[0072] N1 T1 D1

[0073] N2 G41

[0074] N3 G00X=0 Y=0 Z=0

[0075] N4 F10000

[0076] N5 G1 X100

[0077] N6 G1 X0 Y20

[0078] N7 M30

[0079] The part program shown is intended to mill a sharp corner. Generally, the part program cannot be processed as desired because a tool with the part number 202414254 (foreign version, fair copy) is required.

[0080] 11 of a dimension can never generate such a corner. The part program is therefore automatically modified by the CNC control 4 in each channel so that the desired contour is generated with the respective tool as far as technically possible. Machining with spindle 1 (spindle 2A according to FIG. 1) in channel 1 (channel KA) with tool 3A with tool radius R=5mm (in this example also the standard tool; not shown to scale in the figures) of set N5 is carried out to position X=49.505mm, Y=5mm, then an internally generated circular segment with radius=5mm is inserted, after which the inclined movement in set N6 is carried out to position X=-0.981mm, Y=15.097mm.

[0081] The analogous machining with spindle 2 (spindle 2B) in channel 2 (channel KB) using tool 3B with a tool radius R=4.5mm (in this example with a smaller tool radius compared to the standard tool; also not shown to scale in the figures) of set N5 is carried out to position X=54.554, Y=5mm, then an internally generated circular segment with radius=4.5mm is inserted, after which the inclined movement in set N6 continues to position X=-0.883, Y=15.587. The second spindle (with the smaller tool radius) must in this case travel a distance 5.049mm longer in the X-direction to be able to process the part program.

[0082] In practice, such a procedure for creating part programs is common using the functions "tool radius correction" and "bottleneck detection" known from CNC controls.

[0083] The same part program is used in both channels. The contour is generated with a specific tool center path (hereinafter also referred to as "toolpath" or, in this specific embodiment, as "cutter center path") TA or TB, which results from the specified workpiece contour (target contour S) and the radius of the respective cutter. The CNC control 4 includes the "tool radius compensation" function, which is generally known in CNC controls.

[0084] In FIG. 2, for better illustration, the target contour S and the actual contour IA, which can be generated by the correspondingly modified part program, are shown separately from the workpiece 5A. The two contours S and IA differ between the two points PA1 and PA2 by the deviation contour AA generated by the tool 3A in this area. The circular segment with radius RA transitions seamlessly and continuously into the two straight segments of the target contour S at points PA1 and PA2. 202414254 Foreign version Fair copy

[0085] 12

[0086] Figure 2 illustrates the same situation on the right for machine unit MB and the second channel KB, or channel 2 (not shown), of CNC control 4. The workpiece 5B also requires the production of the desired contour S. Unlike the machining of workpiece 5A in machine unit 5A, workpiece 5B is machined in machine unit MB with a smaller tool, namely a milling cutter 3B with a significantly smaller tool radius RB than milling cutter 3A. Despite the smaller tool radius RB, the sharp corner (desired contour S) cannot be machined precisely. Instead, the contour is automatically adjusted by CNC control 4, and the actual contour IB is generated using the tool center path TB shown.Here too, the two contours S (target contour) and IB (actual contour) are shown, which differ between the two points PB1 and PB2 (see deviation contour AB), due to the tool 3B with tool radius RB. Here again, the circular segment with radius RB transitions seamlessly and continuously into the two straight segments of the target contour S at points PB1 and PB2.

[0087] As can be seen further in FIG 2, tool 3B has to travel a longer distance than tool 3A, so that at time t it x is lagging behind tool 3A.

[0088] If the machining process through a sharp corner (FIG 2) is performed with different tools, especially with different tool radius corrections or tool radius wear corrections, and the control system therefore cannot reach the programmed end contour (in this case X=100mm), an offset of over 5mm in the X-direction between the two machining channels will result at the corrected endpoint of block N5. At the end of the programmed contour N6 (at time t = t x The offset will be over 10mm in relation to the path parameter “contour length”, since the channel with the smaller tool diameter has to travel 5mm further into the corner and 5mm further out of the corner (see FIG 2)

[0089] Generally, the following problem arises: if the control system for machine tools has to calculate offset paths to machine the programmed contour with tool radius compensation, and then uses these as the cutter center paths for path calculation, there will always be different cutter center paths in different channels with different tool radii, and thus a more or less significant offset between the machining channels. Although the workpiece geometry or the part program is programmed identically, the cutter center paths will differ.

[0090] 13 always differ by the size of the differential tool radius. The differences in the cutter center paths become more pronounced the greater the contour changes (see the sharp corner in the example according to FIG. 2).

[0091] Twin-spindle machines are used when very high productivity is required in a very small space. In addition, high productivity necessitates high axis dynamics, or the axes are operated at their dynamic limits. As previously described, this results in asynchronous operation in multi-spindle machines, creating a risk of collision. Given the requirement that the machining units move very close to each other and may even share the same guide rail (one axis), even slight temporal and spatial asynchronicity poses a significant risk of collision.

[0092] According to the invention, a new control function is created that preprocesses a part program in such a way that the existing contour description is automatically extended, i.e., additional geometry sets and possibly further "information" are inserted, so that a function such as tool radius correction (generating offset paths) does not have to remove or shorten contour parts (e.g., in bottleneck detection) or contour pieces (parts of a straight line) in order to be able to process them with any tool corrections.

[0093] The parts program according to the example above would automatically be amended as follows:

[0094] N99 G3 X50.014 Y9.974 l=0 J=5 must be extended (possibly only internally, not visible to the machine operator), and block N5 must be automatically shortened (possibly only internally, not visible to the machine operator). The example part program would then look like this:

[0095] Tool “Spindle 1” Channel 1: Tool “Spindle 2” Channel 2:

[0096] L=100 L=100

[0097] R=5 R=4.5

[0098] Parts program for both channels:

[0099] N1 T1 D1

[0100] N2 G41

[0101] N3 G00X=0 Y=0 Z=0 202414254 Foreign version Fair copy

[0102] 14

[0103] N4 F10000

[0104] N5 G1 X100

[0105] N5 G1 X49.505 ; (new shortened set)

[0106] N99 G3X50.014 Y9.974 1=0 J=5 ; (new set, circle segment) N6 G1 X0 Y20 N7 M30

[0107] If the part program is now processed in comparison to the original part program shown above, at the end of set N5 there is only a deviation of 0.5mm between the first and second channel, the difference in the tool radius.

[0108] The part program generated by preprocessing, including all its additionally inserted geometry sets and other information, is selected and started in both channels and processed with different tool corrections (especially tool radius corrections). During processing, differences will only occur on the order of the tool differences.

[0109] The aforementioned effects of the invention are further illustrated below with reference to FIG. 3. Starting with tool 3A of machine unit MA, a new target contour NS is determined, which corresponds to the actual contour IA from FIG. 2. Tool 3A is therefore used as the standard tool with the corresponding standard tool radius RA for generating the new target contour NS. The new target contour NS is designed such that it can be generated with tool 3A (standard tool) without any inherent deviations. In particular, in the corresponding part program generating the new target contour NS, the two straight segments are shortened compared to the previous part program (the first straight segment ends at point PA1, the second straight segment begins at point PA2), and a circular segment with radius RA, corresponding to the deviation contour AA, is inserted between the two points PA1 and PA2.

[0110] Unlike the example shown in FIG. 2, a new target contour NS for the relevant standard tool, i.e., tool 3A in this embodiment, is now also generated for the (smaller) tool 3B of the machine unit MB, in particular by means of a new control function “Geometry preprocessing for offset webs” of the CNC control 4. Analogous to the procedure shown in FIG. 2, the control unit generates the new target contour NS based on the new target contour NS and taking into account the tool radius RB, first using the 202414254 foreign version fair copy

[0111] 15

[0112] The "Tool Radius Correction" function adjusts the tool center path (or toolpath) for tool 3B. As can be seen, this no longer corresponds to the original second toolpath TB from FIG. 2 and is therefore designated as the new second toolpath (tool center path) TB'. This newly created second toolpath is then assigned to tool 3B of machine unit MB for machining the second workpiece 5B. Both machine units thus produce identical actual contours IA = IB = NS.

[0113] FIG 4 illustrates the situation with a target contour profile featuring an obtuse angle between workpieces 5A and 5B. Here, too, tool 3A is considered the standard tool and determines the actually achievable contour profile. If the tool center path TA is specified for tool 3A by a corresponding part program in conjunction with a tool radius correction performed via the CNC control, the contour deviation (deviation contour) AA occurs in the edge area due to the tool radius RA. This deviation contour is then incorporated into the new target contour NS as part of it, and the two straight segments are shortened accordingly. At least one new block is inserted into the original part program to reflect or generate this contour deviation.

[0114] The newly created part program is also crucial for tool 3B of machine unit MB, either by adopting the new part program generated in the machine unit or by generating the same part program in channel KB based on the standard tool data from channel KA. In conjunction with tool radius compensation, the CNC control determines the tool center path (toolpath) TB' for tool 3B, resulting in the same actual contour for workpiece 5B as for workpiece 5A. This is illustrated separately in FIG. 4 as the new target contour NA, which consists of two straight segments and the deviation contour AA.

[0115] Preprocessing or preparing the geometry and starting this preprocessed parts program can help to operate true twin-spindle machines largely synchronously and therefore without collisions, without forced synchronization across channels.

[0116] The invention provides a new control function that can be used with twin or multi-spindle machines and any NC program (applied simultaneously in several channels). 202414254 Foreign version Fair copy

[0117] 16) is applicable. Using two input parameters (maximum static and dynamic distance), the function could easily synchronize a part program across two or more channels for a similar tool, i.e., an identical tool except for tool wear. This allows for further improvement and optimization of highly productive machine tools. Furthermore, the function allows two virtually independent machine tools with the same part program and thus identical workpiece to be built "very close together," minimizing the footprint (machine space in the machine hall), which is becoming an increasingly important purchasing criterion, especially in Europe. Additionally, such multi-spindle machine tools can save energy, as the coolant pump, hydraulic pump, and cooling unit only need to be present once for two machining operations. The new control function, for example...A "geometry preprocessor for offset webs" could be implemented as follows: A geometry preprocessor for offset webs, e.g., for tool correction (e.g., length and diameter of a milling cutter) of a standard tool, calculates a new part program before the actual processing of the part program. This new program ensures that the contour can always be fully generated using the dimensions of the standard tool. This new part program is then used for all (machining) channels or generated identically in all channels. Due to this preprocessing (i.e., the precalculation of the tool correction with respect to the standard tool), only the wear correction (during operation) needs to be individually considered in each channel when processing the new part program. Since tool wear during operation is relatively small, the resulting differences in the channels are either negligible or insignificant.so small that they can be synchronized via temporary synchronization points using explicit WAIT markers or internally generated WAIT markers.

[0118] The introduction of such a control function would increase the processing speed and quality of all components manufactured using these technologies. This technical innovation can significantly improve the efficiency of multi-spindle machines, especially twin-spindle machines.

[0119] Preprocessing allows geometry-specific adjustments, such as tool corrections in sharp corners, to be made to the part program or workpiece being processed. Since these adjustments are implemented within the part program or workpiece itself, they benefit all processing channels equally, meaning that the processing channels only need to implement and execute paths with minor offsets (e.g., due to wear). 202414254 Foreign version Fair copy

[0120] 17

[0121] The new control function, e.g., "Geometry Preprocessor for Offset Webs," could also provide a solution for other tasks. For example, if a machine operator needs to produce identical workpieces with different tool radii, they could use the "Geometry Preprocessor for Offset Webs" function to start preprocessing with their largest available tool, save the result as a new (workpiece) part program, and then use this program to produce identical workpieces with smaller tools. In general, the invention is not limited to multi-spindle machines but can also be applied analogously to single-spindle machines, for example, to produce largely identical workpieces sequentially on one machine or on different machines.

[0122] Key process steps in carrying out a process according to the invention are illustrated in FIG 5.

[0123] In a first process step S1, a target contour for the workpieces is specified to a control device, in particular a numerical or CNC control, of a machine tool for machining at least one first workpiece by means of a first tool with a first tool effective radius and a second workpiece by means of a second tool with a second tool effective radius.

[0124] In a second process step S2, the control unit determines a first toolpath for a first tool with a first tool radius from the data relating to the target contour to generate a first target contour, whereby, due to a curvature or an edge in the first target contour, the first target contour cannot be generated without errors with the first tool due to the first tool radius, but only in the form of a first actual contour, which includes a first deviation contour in the area of ​​the curvature or the edge compared to the first target contour.

[0125] In process step S3, the control unit generates a new target contour that includes the deviation contour.

[0126] In a fourth process step S4, the control unit determines a new second toolpath for the second tool, depending on the second tool's effective radius, to generate the new target contour (NS). 202414254 Foreign version Fair copy

[0127] 18

[0128] In a fifth process step S5, the second workpiece is machined according to the new second toolpath.

Claims

202414254 Foreign version Fair copy 19 Patent claims 1. Method for machining at least one first workpiece (5A) using a first tool (3A) with a first tool radius (RA) and a second workpiece (5B) using a second tool (3B) with a second tool radius (RB), wherein a target contour (S) is specified for the workpieces (5A, 5B), wherein a first toolpath (TA) for the first tool (3A) is determined as a function of the first tool radius (RA), wherein, due to a curvature, a corner, or an edge in the target contour (S), the target contour (S) cannot be produced flawlessly with the first tool (3A) because of the first tool radius (RA), but only in the form of a first actual contour (IA), which includes a first deviation contour (AA) from the target contour (S) in the area of ​​the curvature, corner, or edge, wherein a new target contour (NS) is generated which replaces the deviation contour (AA). includeswherein a new second toolpath (TB') for the second tool (3B) is determined depending on the second tool working radius (RB) to generate the new target contour (NS), wherein the first workpiece (3A) is machined according to the first toolpath (TA) and the second workpiece (3B) according to the new second toolpath (TB').

2. Method according to claim 1, wherein the first tool (3A) is a standard tool with a standard tool working radius.

3. Method according to claim 1 or 2, wherein the first tool (3A) and the second tool (3B) are each milling tools.

4. Method according to one of the preceding claims, wherein the tool working radius (RB) of the second tool (3B) is smaller than the tool working radius (RA) of the first tool (3A).

5. Method according to one of the preceding claims, wherein a second workpiece (5B) different from the first workpiece (5A) is machined using the second tool (3B).

6. Method according to one of the preceding claims, wherein the deviation contour (AA) is determined based on the first tool effective radius (RA) of the first tool (3A). 202414254 Foreign version Fair copy 20 7. Method according to one of the preceding claims, wherein the target contour (S) is represented in the form of sets of a part program and the new target contour (NS) is represented in the form of new sets of a new part program, and wherein the part program and the new part program differ in that the new part program comprises at least one new set that represents the deviation contour (AA).

8. Control device (4) for a machine tool (2) for machining at least one first workpiece (5A) by means of a first tool (3A) with a first tool effective radius (RA) and a second workpiece (5B) by means of a second tool (3B) with a second tool effective radius (RB), in particular for carrying out a method according to one of claims 1 to 7, wherein a target contour (S) for the workpieces (5A, 5B) can be specified, wherein a first toolpath (TA) for the first tool (3A) can be determined by means of the control device (4) and a correction device included therein as a function of the first tool effective radius (3A), wherein due to a curvature, a corner or an edge in the first target contour (S) the first target contour (S) cannot be produced without errors with the first tool (3A) due to the first tool effective radius (RA), but only in the form of a first actual contour (IA) which in the area of ​​the Curvature,the corner or edge comprises a first deviation contour (AA) compared to the first nominal contour (S), wherein a new nominal contour (NS) can be generated which includes the deviation contour (AA), wherein a new second toolpath (TB') for the second tool (3B) can be determined depending on the second tool effective radius (RB) to generate the new nominal contour (NS), wherein the first workpiece (3A) can be machined according to the first toolpath (TA) and the second workpiece (5B) can be machined according to the new second toolpath (TB').

9. Control device (4) according to claim 8, wherein a second workpiece (5B) different from the first workpiece (5A) can be machined by means of the second tool (3B).

10. Control device (4) according to claim 8 or 9, wherein the deviation contour (AA) can be determined based on the first tool effective radius (RA) of the first tool (3A).

11. Control device (4) according to one of claims 8 to 10, wherein the target contour (S) can be represented in the form of sets of a part program and the new target contour (NS) in the form 202414254 Foreign version Fair copy 21 of new sets of a new part program, wherein the part program and the new part program differ in that the new part program comprises at least one new set that maps the deviation contour (AA).

12. Control device (4) according to one of claims 8 to 11, configured as a CNC control (4).

13. Machine tool system (1) comprising a machine tool (2) and a control device (4) according to one of claims 8 to 12 for carrying out a method according to one of claims 1 to 7.

14. Machine tool system (1) according to claim 13, comprising a multi-spindle machine tool (2).

15. Digital twin of a machine tool system (1) according to claim 13 or 14 for Simulation of a method according to any one of claims 1 to 7.

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