Method for dynamic compensation of angular errors in the case of operating a machine tool and machine tool operable with such a method

Abstract

The invention relates to a method for dynamically compensating angular errors in the context of operating a machine tool (2), comprising at least one holder (4) for at least one workpiece (6), in or at which the workpiece (6) can be fixed, at least one tool holder (8), in which a tool (10), in particular a drill, is fixed and can be driven in rotation by a rotary drive (12) of the tool holder (8), at least one horizontal drive (14), by which the tool holder (8) can be moved at least in a horizontal plane of the machine tool (2) in order to machine the workpiece (6), at least one vertical drive (16), by which the tool holder (8) can be moved in a vertical direction of the machine tool (2), and at least one control unit (18), which is functionally associated with the rotary drive (12), the horizontal drive (14) and the vertical drive (16).

Description

Technical Field

[0001] The present invention relates to a method for dynamically compensating for angular errors in the operation of a machine tool, and a machine tool that can operate in such a manner. Background Technology

[0002] It is known from the prior art that angular errors may occur during machine tool operation, especially when the cutting tool is removed from a freshly machined workpiece. These angular errors may cause scratches in drilling, leading to a reduction in work quality during workpiece machining.

[0003] The reason for this is that the force acting along the Z-axis extending in the horizontal plane cannot be absorbed by the frame without connection during workpiece acceleration or machining. This results in an angular error in the vertical direction. Summary of the Invention

[0004] The object of one embodiment of the present invention is to provide a method for dynamically compensating for angular errors in the case of operating a machine tool, and a machine tool that can be operated in such a way that the quality of the workpiece to be processed is improved.

[0005] This objective is achieved by a method for dynamically compensating for angular errors during the operation of a machine tool, the machine tool comprising: at least one support for at least one workpiece, wherein the workpiece can be fixed; at least one tool holder, wherein a tool, particularly a drill bit, is fixed and can be rotatably driven by a rotary drive of the tool holder; at least one horizontal drive, through which the tool holder can be moved at least in the horizontal plane of the machine tool for machining the workpiece; at least one vertical drive, through which the tool holder can be moved in the vertical direction of the machine tool; and at least one control unit functionally associated with the rotary drive, the horizontal drive, and the vertical drive, the method comprising the following steps:

[0006] a. Moving at least one rotary-driven tool into the workpiece along an infeed direction extending in or inclined to a horizontal plane for machining the workpiece;

[0007] b. The rotary-driven tool is removed from the workpiece along the removal direction opposite to the insertion direction, and the actual position of the tool holder in the vertical direction and the actual values ​​of the force and / or acceleration of the tool about the Z-axis extending in the horizontal plane are detected.

[0008] c. The angular error of the tool depends on the actual values ​​of the force and / or acceleration pre-control of the tool about the Z-axis extending in the horizontal plane;

[0009] d. Determine the compensation value of the tool holder in the vertical direction to compensate for the determined angular error, and transfer the tool holder from the actual position to the rated position with the determined compensation value.

[0010] By pre-controlling the actual value of the force and / or acceleration of the tool about the Z-axis extending in the horizontal plane, the angular error can be determined, and a compensation value can be determined. The tool holder can then be moved from its actual position to its rated position with the determined compensation value. The angular error can be compensated by moving the tool holder. This reduces damage to the workpiece being machined, and in particular, lowers the risk of so-called scratches.

[0011] The determined angular error of the tool can be determined based on the actual values ​​of the tool's force pre-control and / or the actual values ​​of the tool's acceleration pre-control.

[0012] This allows us to determine the connection of the cutting tool with respect to the frame.

[0013] Angular error is understood as the deviation between the longitudinal axis of the tool and the Z-axis in the horizontal plane.

[0014] To ensure the real-time machining of the workpiece and the operation of the method, it has been proven advantageous that the control unit includes at least one storage unit in which at least one table in which multiple table values ​​can be stored and / or a calculation model through which table values ​​can be calculated is stored, wherein the actual values ​​of force and / or acceleration pre-controlled in the direction of the Z-axis extending in the horizontal plane of the tool are associated with the angular error and / or compensation value of the tool holder in the vertical direction, either in the table or through the calculation model.

[0015] By storing the pre-controlled actual values ​​of tool force and / or acceleration and the tool holder compensation value, angular errors or compensation values ​​can be detected quickly and easily. The reservation of multiple table values ​​eliminates the need for calculations, thereby enabling faster execution of the method or its steps.

[0016] When a computational model can be stored in the storage unit, the reservation of multiple table values ​​can be cancelled, and the angle error and / or compensation values ​​can be determined as needed. Thus, the control unit can be used immediately without first requiring training through the creation and reservation of multiple table values.

[0017] Furthermore, in one embodiment of this method, a combination of two feasible solutions is provided, thereby calculating multiple table values ​​through a computational model and storing them in a table. This allows the already calculated table values ​​to be used without recalculating them, thus accelerating the manipulation of the tool holder for vertical transfer.

[0018] In an improved version of this method, the compensation value is configured to include a correction curve or correction data for the tool holder in the vertical direction to compensate for a determined angular error.

[0019] When the compensation value includes the correction curve, the movement of the tool along the Z-axis can be directly coupled with the movement of the tool holder in the vertical direction.

[0020] When the compensation value includes the correction data of the tool holder in the vertical direction, the compensation value becomes particularly dependent on the stepwise calculation of the tool position.

[0021] The actual values ​​of the tool force and / or acceleration pre-control can be easily and cost-effectively detected when the actual values ​​of the tool force and / or acceleration pre-control in the direction of the Z-axis extending in the horizontal plane can be detected by the control unit from the data of the rotary drive and / or by the sensor.

[0022] When the actual values ​​of the pre-controlled force and / or acceleration of the tool can be detected by the control unit from the data of the rotary drive, the machine tool can be compactly constructed, especially without the need for additional sensors. When the actual values ​​of the pre-controlled force and / or acceleration can be detected by sensor components, the accuracy of the detected data can be improved.

[0023] Furthermore, in some implementations of this method, a combination of detection by a control unit and detection by a sensor may be provided.

[0024] Furthermore, this method can be easily and cost-effectively implemented when the actual position of the tool holder in the vertical direction can be detected by the control unit from data from the vertical driver and / or by a sensor.

[0025] As a supplement to or alternative to the above embodiments, in an improved version of the method, the determination of the tool angle error based on the actual values ​​of the force and / or acceleration pre-control of the tool about the Z-axis extending in the horizontal plane is achieved by a computational model or by a sensor device.

[0026] In this case, the angular error can be calculated from the actual values ​​of the tool force and / or acceleration pre-control by a computational model or determined directly by the sensor device. As previously described, the angular error can also be correlated with the actual values ​​of the tool force and / or acceleration pre-control in a table in the storage unit.

[0027] To further improve the quality of dynamic compensation for angular errors in the case of running machine tools, it has been proven advantageous to include detecting the actual position of the tool in the horizontal plane.

[0028] In one improved embodiment of the last mentioned example, the dynamic compensation of angular error in the case of a running machine tool can be further improved by determining the compensation value of the tool holder in the vertical direction, which additionally depends on the actual position of the tool detected in the horizontal plane.

[0029] In principle, it is possible for the machine tool to include only a single vertical drive. When the machine tool includes multiple tool holders, each of which can be positioned to hold a tool and can be moved together to machine a workpiece, it proves advantageous for the machine tool to include at least two vertical drives, through which the tool holders can be moved in the vertical direction of the machine tool, and the detection of the actual position of the tool holders in the vertical direction can be achieved by a control unit using data from the two vertical drives and / or by sensors.

[0030] The following is possible in an implementation of the method, in which the machine tool can operate at a defined maximum machining speed (where the actual value of the tool force and / or acceleration pre-control is maximum) and / or at an adjustable machining speed (where the actual value of the tool force and / or acceleration pre-control is reduced with respect to the value in the case of maximum machining speed).

[0031] The machining time is minimized when the machine tool can operate at its defined maximum machining speed (where the actual values ​​of the tool force and / or acceleration pre-control are at their maximum). However, the angular error is also at its maximum under these conditions.

[0032] When the machine tool is operated at an adjustable machining speed (where the actual values ​​of the tool force and / or acceleration pre-control are reduced relative to the values ​​in the case of maximum machining speed), the machining time of the workpiece is increased. However, in this case, angular errors can be reduced.

[0033] The implementation of this method is characterized by the one-time or periodic execution of the method steps, wherein the periodic execution includes time intervals of less than one second, less than half a second, and less than one millisecond for the method to be executed again.

[0034] Furthermore, the method can be implemented in a manner in which the tool holder is transferred abruptly or continuously from its actual position to its rated position by a determined compensation value.

[0035] When the tool holder is suddenly transferred from its actual position to its rated position by a determined compensation value, or when the tool switches from a movement into the workpiece to a movement out of the workpiece, the transfer of the tool holder from its actual position to its rated position by a determined compensation value can be achieved, for example.

[0036] When the tool holder is continuously transferred from its actual position to its rated position with a determined compensation value, the inertial effect during the transfer can be reduced.

[0037] Finally, this objective is achieved by a machine tool comprising: at least one support for at least one workpiece, wherein the workpiece can be fixed; at least one tool holder, wherein a tool, particularly a drill bit, is fixed and can be rotatably driven by a rotary drive of the tool holder; at least one horizontal drive by which the tool holder is movable at least in the horizontal plane of the machine tool for machining the workpiece; at least one vertical drive by which the tool holder is movable in the vertical direction of the machine tool; and at least one control unit functionally associated with the rotary drive, the horizontal drive, and the vertical drive, wherein the machine tool operates according to a method of dynamic angular error compensation having the previously mentioned features. Attached Figure Description

[0038] Further features, details and advantages of the invention will become apparent from the appended patent claims, the accompanying drawings and the following description of preferred embodiments of the method and machine tool.

[0039] in:

[0040] Figure 1 A schematic side cross-sectional view of a certain area of ​​the machine tool is shown;

[0041] Figure 2 A schematic flowchart of the method according to the present invention is shown.

[0042] List of reference numerals

[0043] 2 machine tools

[0044] 4 supports

[0045] 6 workpieces

[0046] 8-knife clip

[0047] 10 knives

[0048] 12 Rotary Drives

[0049] 14 horizontal drives

[0050] 16 Vertical Drives

[0051] 18 control units Detailed Implementation Plan

[0052] Figure 1 A schematic diagram of a machine tool (shown only partially) generally indicated by reference numeral 2 is shown. This machine tool includes a support 4 for a workpiece 6. The workpiece 6 is fixed at the support 4. Furthermore, the machine tool 2 includes a tool holder 8 in which a cutting tool 10, particularly a drill bit, is fixed. The cutting tool 10 can be rotated via a rotary drive 12 of the tool holder 8.

[0053] Furthermore, the machine tool 2 includes a horizontal drive 14, through which the tool holder 8 can be moved at least in the horizontal plane of the machine tool 2 for machining the workpiece 6. Additionally, the machine tool 2 includes a vertical drive 16, through which the tool holder 8 can be moved in the vertical direction of the machine tool 2.

[0054] Finally, the machine tool 2 includes a control unit 18, which is functionally associated with the rotary drive 12, the horizontal drive 14, and the vertical drive 16.

[0055] In the use of Figure 1 In this case, the following describes the situation based on Figure 2 A schematic flowchart.

[0056] In the first step 100, at least one rotary-driven tool 10 is moved into the workpiece 6 along an infeed direction extending in or inclined to a horizontal plane in order to process the workpiece 6.

[0057] Here, workpiece 6 is machined by tool 10. After machining of workpiece 6, tool 10, which was rotated in step 101, is removed from workpiece 6 in an outward direction opposite to the inward direction. Here, the actual position of tool holder 8 in the vertical direction is detected, and the actual values ​​of force and / or acceleration pre-control of tool 10 about the Z-axis extending in the horizontal plane are detected.

[0058] In the next step 102, the angular error of the tool 10 is determined based on the actual values ​​of the force and / or acceleration pre-control of the tool 10 about the Z-axis extending in the horizontal plane.

[0059] In the next step 103, a compensation value for the tool holder 8 in the vertical direction is determined to compensate for the determined angular error, and the tool holder 8 is transferred from the actual position to the rated position with the determined compensation value.

[0060] The features of the invention disclosed in the foregoing description, in the claims, and in the drawings are important not only individually but also in arbitrary combinations in carrying out the invention in its various embodiments.

Claims

1. A method for dynamically compensating for angular errors during the operation of a machine tool (2), the machine tool comprising: At least one support (4) for at least one workpiece (6), wherein the workpiece (6) can be fixed; at least one tool holder (8), wherein a tool (10) or a drill bit is fixed and can be rotated by a rotary drive (12) of the tool holder (8); at least one horizontal drive (14) by which the tool holder (8) can be moved at least in the horizontal plane of the machine tool (2) for machining the workpiece (6); at least one vertical drive (16) by which the tool holder (8) can be moved in the vertical direction of the machine tool (2); and at least one control unit (18) functionally associated with the rotary drive (12), the horizontal drive (14) and the vertical drive (16), the method comprising the following steps: a. The at least one rotary-driven tool (10) is moved into the workpiece (6) along an infeed direction extending in or inclined to a horizontal plane for machining the workpiece (6); b. The rotary-driven tool (10) is removed from the workpiece (6) along the removal direction opposite to the insertion direction and the actual position of the tool holder (8) in the vertical direction and the actual values ​​of the force and / or acceleration of the tool (10) about the Z-axis extending in the horizontal plane are detected. c. The angular error of the tool (10) is determined based on the actual values ​​of the force and / or acceleration pre-control of the tool (10) about the Z-axis extending in the horizontal plane; d. Determine the compensation value of the tool holder (8) in the vertical direction for compensating the determined angular error and transfer the tool holder (8) from the actual position to the rated position with the determined compensation value.

2. The method according to claim 1, characterized in that, The control unit (18) includes at least one storage unit in which at least one table in which multiple table values ​​can be stored and / or through which the table values ​​can be calculated is stored, wherein the actual values ​​of force and / or acceleration pre-control of the tool (10) in the direction of the Z-axis extending in the horizontal plane are associated with the angular error and / or compensation value of the tool holder (8) in the vertical direction, as shown in the table or through the calculation model.

3. The method according to claim 1 or 2, characterized in that, The compensation value includes the correction curve or correction data of the tool holder (8) in the vertical direction for compensating for the determined angular error.

4. The method according to claim 2, characterized in that, The actual values ​​of the force and / or acceleration pre-control of the cutting tool (10) in the direction of the Z-axis extending in the horizontal plane can be detected by the control unit (18) from the data of the rotary drive (12) and / or by the sensor.

5. The method according to claim 2, characterized in that, The actual position of the blade holder (8) in the vertical direction can be detected by the control unit (18) using data from the vertical driver (16) and / or by a sensor.

6. The method according to claim 4 or 5, characterized in that, The determination of the angular error of the cutting tool (10) depends on the actual value of the force and / or acceleration of the cutting tool (10) about the Z-axis extending in the horizontal plane, which is achieved by the calculation model or by the sensor device.

7. The method according to claim 2, characterized in that... In the case of a determined actual value of force and / or acceleration pre-control, the actual angular error is determined by manually inputting the table value stored in the table, running the calculation model and / or detecting the determined actual angular error, wherein at least one actual value of force and / or acceleration pre-control in the direction of the Z-axis extending in the horizontal plane of the tool in the table is associated with the angular error and / or compensation value of the tool holder (8) in the vertical direction.

8. The method according to claim 1, characterized in that... The actual position of the cutting tool (10) in the horizontal plane is detected.

9. The method according to claim 8, characterized in that, The determination of the compensation value of the tool holder (8) in the vertical direction depends additionally on the actual position of the tool (10) in the horizontal plane as detected.

10. The method according to any one of claims 4 or 5, characterized in that, The machine tool (2) includes at least two vertical drives (16), through which the tool holder (8) can be moved in the vertical direction of the machine tool (2), and the detection of the actual position of the tool holder (8) in the vertical direction can be achieved by the control unit (18) using data from the two vertical drives (16) and / or by the sensor device.

11. The method according to claim 1, characterized in that, The machine tool (2) can operate at a defined maximum machining speed and / or at an adjustable machining speed, wherein the actual value of the pre-controlled force and / or acceleration of the tool (10) is maximized at the defined maximum machining speed, and wherein the actual value of the pre-controlled force and / or acceleration of the tool (10) is reduced with respect to the value at the maximum machining speed at the adjustable machining speed.

12. The method according to claim 1, characterized in that... The method steps are executed once or periodically, wherein the periodic execution includes time intervals of less than one second, less than half a second, and less than one millisecond for the time interval between re-executions of the method.

13. The method according to claim 1, characterized in that, The blade holder (8) is transferred suddenly or continuously from the actual position to the rated position by a determined compensation value.

14. A machine tool (2) comprising: at least one support (4) for at least one workpiece (6), wherein the workpiece (6) may be fixed therein or thereon; at least one tool holder (8) in which a cutting tool (10) or a drill bit is fixed and may be rotatably driven by a rotary drive (12) of the tool holder (8); at least one horizontal drive (14) by which the tool holder (8) may be moved at least in the horizontal plane of the machine tool (2) for machining the workpiece (6); at least one vertical drive (16) by which the tool holder (8) may be moved in the vertical direction of the machine tool (2); and at least one control unit (18) functionally associated with the rotary drive (12), the horizontal drive (14) and the vertical drive (16), wherein, The machine tool (2) can be operated according to any one of claims 1 to 13 for the method of dynamically compensating for angular errors.

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