Measuring system for machine tools, machine tool and method for determining tool coordinates of a tool of a machine tool

Abstract

The invention relates to a measuring system for a machine tool, in particular for a lathe, for automatically determining tool coordinates of a tool of the machine tool, wherein the measuring system comprises a touch sensor which carries a touch element defining a touch element coordinate system and is configured to generate a touch signal upon contact of the touch element, in particular with the tool of the machine tool, wherein the touch element has at least one touch surface defining a touch surface normal vector, wherein the touch surface normal vector extends perpendicular to the at least one touch surface and defines a touch axis, wherein the touch element has at least one touch surface defining a touch element surface normal vector, wherein the touch element surface normal vector extends perpendicular to the touch element surface and defines a touch element axis.wherein the stylus surface normal vector and the stylus surface normal vector are linearly independent of each other, characterized in that the stylus has at least one inclined stylus surface defining an inclined stylus surface normal vector, that the inclined stylus surface normal vector is perpendicular to the inclined stylus surface, that the inclined stylus surface is inclined relative to the stylus surface and relative to the stylus surface, and that the inclined stylus surface normal vector is formed by vector addition from multiples of the stylus surface normal vector and the stylus surface normal vector. Furthermore, an improved machine tool and a method for determining the tool coordinates of a tool of a machine tool are proposed.

Description

[0001] The present invention relates to a measuring system for a machine tool, in particular for a lathe, for automatically determining tool coordinates of a tool of the machine tool, wherein the measuring system comprises a touch sensor which carries a touch body defining a touch body coordinate system and is designed to generate a touch signal upon contact with the touch body, in particular with the tool of the machine tool, wherein the touch body has at least one touch surface defining a touch surface normal vector, wherein the touch surface normal vector runs perpendicular to the at least one touch surface and defines a touch axis, wherein the touch body has at least one touch body surface defining a touch body surface normal vector, wherein the touch body surface normal vector runs perpendicular to the touch body surface and defines a touch body axis,where the touch surface normal vector and the touch body surface normal vector are linearly independent of each other.

[0002] Furthermore, the present invention relates to a machine tool, in particular a lathe, for machining a workpiece with a tool, wherein the machine tool defines a machine coordinate system and comprises a measuring system for automatically determining tool coordinates of a tool of the machine tool.

[0003] Furthermore, the invention relates to a method for determining tool coordinates of a tool of a machine tool, in particular a lathe, using a measuring system.

[0004] Measuring systems for machine tools of the type described above are known in various forms. They serve the purpose of enabling the tool moved by the machine tool to be positioned with high precision for machining a workpiece. For this purpose, the position of the tool in the coordinate system of the machine tool is determined using the measuring system during referencing or calibration. The tool moves toward the probe body. If this is touched, the touch sensor generates a touch signal, the tool movement is stopped, and at least one coordinate of the contact point between the tool and the probe body is assigned to the tool.

[0005] In the manner described, it is known to reference or calibrate tool coordinates in two axes on lathes. These are typically the Z-axis, which is defined by the rotational axis around which the workpiece is rotated by the lathe for machining, and an axis perpendicular to the Z-axis, commonly referred to as the X-axis. The Z-axis and the X-axis define a work plane.

[0006] Determining or referencing a tool position in an axial direction perpendicular to the work plane, i.e., in a direction referred to below as the Y-axis, is not yet known. Determining a tool coordinate in the Y-direction in the machine tool's coordinate system enables even more precise positioning of the tool and thus even more accurate machining of the workpiece.

[0007] DE 20 2015 004 771 U1 discloses a position detection device for detecting the position of a tool. DE 299 16 325 U1 describes a device for measuring parameters on CNC machining centers.

[0008] It is therefore an object of the present invention to improve a measuring system, a machine tool and a method of the type described above such that a position of the tool can be determined in all three spatial directions.

[0009] This object is achieved according to the invention in a measuring system of the type described at the outset in that the probe body has at least one inclined probe surface defining an inclined probe surface normal vector, that the inclined probe surface normal vector runs perpendicular to the inclined probe surface, that the inclined probe surface is inclined relative to the probe surface and relative to the probe body surface, and that the inclined probe surface normal vector is formed by vector addition from multiples of the probe surface normal vector and the probe body surface normal vector.

[0010] Such a measuring system makes it possible, in particular, to determine the position of the tool in the direction of the probe axis. This is achieved by not moving the tool against the probe surface until it touches it. Rather, the specially designed probe determines a coordinate of the tool in the probe coordinate system or in the coordinate system of the machine tool based on the offset of the tool relative to the probe surface when the tool touches the inclined probe surface.If the shape of the probe body is known, in particular the course of the probe surface and the inclined probe surface relative to one another and / or the probe body surface and the inclined probe surface relative to one another, the position of the tool in the direction of the probe body axis and thus a coordinate in this direction can be determined and assigned to the tool from the change in the position of the tool in the direction of the probe axis by comparing the contacts or contact points of the tool with the probe surface and the inclined probe surface. This configuration has the particular advantage that optionally only a movement parallel to the probe axis in the direction of the probe surface or in the direction of the inclined probe surface is required to determine a coordinate in a direction transverse, in particular perpendicular to the probe axis, namely in the direction of the probe body axis.This simplifies control of the measuring system and the machine tool in order to reference the tool in the desired manner and with high precision. As explained, the proposed measuring system makes it possible to determine a coordinate value of the tool in the direction of the probe body axis without the tool having to touch the probe body surface. This is not possible with some types of machine tools, so the proposed measuring system also enables tool reference in the direction of the probe body axis on these machines. Optionally, the tool can also be moved parallel to the probe body axis to reference a coordinate value until the tool touches the probe body in the area of ​​the inclined probe surface.In particular, the proposed measuring system enables precise calibration or referencing of the tool, even when a tool edge designed for machining a workpiece runs parallel to a sensing surface or a sensing body surface. By designing at least one inclined sensing surface running at an angle to these, a defined contact point or, if necessary, a contact line can be specified, which enables significantly higher accuracy in tool referencing than surface contact of the tool with a sensing surface or a sensing body surface.

[0011] The measuring system can be designed particularly easily if the probe body coordinate system is a Cartesian coordinate system. For example, this can be specified by having at least one probe surface and at least one probe body surface perpendicular to each other.

[0012] According to a further preferred embodiment, it can be provided that the measuring system comprises a positioning arm which is arranged on a machine tool or can be arranged on a machine tool, and that the touch sensor is arranged or formed on the positioning arm. In particular, it can be arranged or formed at a free end of the positioning arm. This configuration makes it possible, in particular, to arrange the touch probe on the machine tool at a position where it does not interfere with the machining of workpieces as much as possible, but where the tool can be moved reliably and precisely towards the touch probe in order to determine its coordinates in the touch probe coordinate system and, if its position and orientation in the coordinate system of the machine tool are known, also in the coordinate system of the machine tool.

[0013] Preferably, the probe body is designed to be detachably connectable to the positioning arm. In particular, the probe body can be detachably connectable to the touch sensor. In particular, probe bodies can be provided for different tools and machine tools, which can then be coupled to the positioning arm or the touch sensor in a defined manner in order to perform the desired measurement or referencing of the tool. Alternatively, the positioning arm can also be permanently mounted on the machine tool. In particular, it can be mounted on the machine tool in a movable, for example pivotable, manner.

[0014] It is advantageous if the measuring system includes an interface device for unambiguously coupling the probe body to the positioning arm in a measuring position. Such an interface device can ensure, in particular, that referencing of a tool can be carried out with high precision even if the probe body has been replaced. For this purpose, it is particularly intended that the interface device specifies the position and orientation of the probe body on the positioning arm with high precision. "Unambiguous" in this sense means that there is only one way to couple the probe body to the positioning arm in the measuring position, both in terms of relative position and relative orientation.

[0015] The measuring system can be easily configured if the interface device comprises first and second interface elements that engage with each other in the measuring position and are disengaged in a cleaning position. By engaging the first and second interface elements, the probe body can be easily and reliably coupled to the positioning arm or the probe sensor.

[0016] In order to enable referencing of a tool in a Cartesian coordinate system, it is advantageous if the at least one sensing surface and the at least one sensing body surface run perpendicular to one another.

[0017] According to a further preferred embodiment, it can be provided that the at least one tactile surface and the at least one inclined tactile surface enclose a first interior angle, that the at least one tactile body surface and the at least one inclined tactile surface enclose a second interior angle, and that an angle sum of the first interior angle and the second interior angle is 270°. Such a configuration makes it possible, in particular, to form the at least one inclined tactile surface by chamfering an edge between the tactile surface and the tactile body surface. By specifying the interior angle, a profile of the at least one inclined tactile surface relative to the at least one tactile surface and relative to the at least one tactile body surface can be precisely specified, which is necessary for determining the coordinate in the direction of the tactile body axis.

[0018] Advantageously, the first interior angle and the second interior angle have an identical value of 135°. This makes it possible, in particular, to form a very simple probe body in which the at least one probe surface and the at least one probe body surface extend perpendicular to each other, and the at least one inclined probe surface is inclined by 45° relative to the at least one probe surface and the at least one probe body surface.

[0019] It is advantageous if the probe body has at least two contact surfaces whose contact surface normal vectors are linearly independent of each other. For example, contact surfaces pointing in the Z-axis direction on the one hand and in the X-axis direction on the other can be used to reference a coordinate of the tool in the Y-axis direction.

[0020] For a Cartesian coordinate system, it is advantageous if at least two touch surfaces are perpendicular to each other. As explained, the two touch surfaces can define the X-axis and the Z-axis through their touch surface normal vectors and thus also run perpendicular to the working plane, the XZ plane.

[0021] To be able to reference a wide variety of tools in different tool holders, it is advantageous if the probe body has four contact surfaces. This makes it possible, in particular, to touch the probe body with a tool on the four contact surfaces in order to reference its position in the coordinate system of the machine tool or in the probe body coordinate system, particularly in a direction parallel to a probe axis.

[0022] The sensing element can be designed particularly easily if the four sensing surfaces run parallel to each other in pairs. This design makes it particularly possible to form the sensing element as a cuboid.

[0023] Furthermore, it is advantageous if the probe body has two probe body surfaces. Such a configuration makes it possible, in particular, to determine coordinates of the tool in the positive and negative directions of the probe body axis. Accordingly, such a probe body preferably also comprises inclined probe surfaces that border both probe body surfaces. In particular, at least one inclined probe surface should border each of the probe body surfaces. In particular, one, two, three, or four inclined probe surfaces can be assigned to each probe body surface in order to determine coordinates in the direction of the probe body axis from coordinates in the direction of one or two probe axes by touching the tool with the probe body on at least one probe surface and at least one inclined probe surface assigned to this.

[0024] Preferably, the two probe surfaces run parallel to each other. This makes it possible, in particular, to design the probe in the shape of a cuboid.

[0025] It is advantageous if the at least one sensing surface and the at least one stylus surface define a common edge and if this edge is chamfered by forming the at least one inclined sensing surface. As already explained, the at least one inclined sensing surface serves to determine a coordinate in the direction of the stylus axis from an offset of the contact coordinate in the direction of a stylus axis for cases where the tool touches the stylus surface during a first measurement and the inclined stylus surface during a further measurement. However, it is also possible to determine a coordinate in the direction of the stylus axis from an offset of the contact coordinate of the contact point between the tool and the inclined stylus surface in the direction of the stylus axis if the course of the at least one stylus surface relative to the at least one inclined stylus surface is known in the stylus coordinate system and / or in the coordinate system of the machine tool.

[0026] In order to provide the largest possible measuring surface, it is advantageous if the common edge is chamfered over its entire length to form at least one inclined scanning surface.

[0027] According to a further preferred embodiment, it can be provided that the at least one inclined touch surface and the at least one touch surface define a first inclined touch surface edge, and that the at least one inclined touch surface and the at least one touch body surface define a second inclined touch edge surface. In other words, the at least one inclined touch surface forms the first inclined touch surface edge together with the at least one touch surface, and the second inclined touch surface edge together with the at least one touch body surface.

[0028] A geometrically simple sensing body can be formed, in particular, if the first and second edges of the inclined sensing surface run parallel to each other. This is easily achieved if a cuboid is used as the base body of the sensing body, with at least one of the twelve edges of the cuboid being chamfered to form an inclined sensing surface.

[0029] It is advantageous if the first and / or second inclined probe surface edges run parallel to a probe surface normal vector. This allows tools to be easily and reliably referenced in the machine tool's coordinate system.

[0030] It is advantageous if the probe surface normal vector defines an X-axis or Z-axis of a machine tool's coordinate system, and if the probe surface normal vector defines a Y-axis of the machine tool's coordinate system. As already explained, the probe surfaces and their probe axes thus define the work plane, with the Y-axis running transversely, in particular perpendicularly, to it.

[0031] Tool coordinates can be easily determined if the machine tool's coordinate system is a Cartesian coordinate system. This makes it possible, especially if the probe body coordinate system is also a Cartesian coordinate system, to easily convert the two coordinate systems into one another by simply translating and / or rotating them.

[0032] The measuring system can be easily configured if the probe body is cuboid-shaped or substantially cuboid-shaped. At least one, in particular any number, of the twelve edges of this probe body is or are at least partially, in particular completely, chamfered to form an inclined sensing surface.

[0033] The sensing element can be designed particularly easily if the at least one sensing surface and / or the at least one inclined sensing surface and / or the at least one sensing element surface are rectangular. In particular, they can be square. In particular, all of the aforementioned surfaces can be rectangular, preferably square.

[0034] Furthermore, it is advantageous if the measuring system comprises a data processing device for calculating a second coordinate value of the tool in the direction of the probe body axis from two first coordinate values ​​of the tool in the direction of the probe axis, which are measured upon contact with, on the one hand, the at least one probe surface and, on the other hand, the at least one inclined probe surface. Provided that the probe body and its outer contour are known, in particular the profile of the at least one probe surface and the profile of the at least one inclined probe surface relative to the at least one probe surface and / or the profile of the at least one inclined probe surface relative to the at least one probe body surface, second coordinate values ​​can thus be calculated as already explained without the tool having to touch the probe body surface. Depending on the shape and / or orientation of the tool, this may either not be possible or would be disadvantageous from a metrological perspective.

[0035] Preferably, the data processing device and the touch sensor are operatively connected for transmitting touch signals. Such an operative connection can be wired or wireless, for example, via a radio network.

[0036] Conveniently, the data processing device comprises a storage device for storing probe body data that defines surfaces of the probe body, in particular the at least one probe surface and the at least one probe body surface. Once the probe body data is stored in the storage device, a coordinate in the direction of the probe body axis can be calculated, as explained, taking this probe body data into account by determining two contact coordinates of the tool with the at least one probe surface and the at least one inclined probe surface.

[0037] The object stated at the outset is further achieved according to the invention in a machine tool of the type described at the outset in that the measuring system is designed in the form of one of the embodiments of measuring systems described above.

[0038] Such a machine tool has in particular the advantages already described above in connection with advantageous embodiments of measuring systems.

[0039] Advantageously, the probe body is arranged on the machine tool in such a way that the probe body coordinate system defines the machine coordinate system, or vice versa. In particular, the probe body coordinate system and the machine tool coordinate system can be designed as Cartesian coordinate systems, which can be converted into one another by simply shifting the origin without rotation.

[0040] The object stated at the outset is further achieved according to the invention in a method of the type described at the outset in that a measuring system is provided in the form of one of the advantageous embodiments of measuring systems described above, in that for a first measurement the tool is moved from a first starting position, in which it does not touch the probe body, in a scanning direction which is not parallel to the probe body surface normal vector, towards the probe body until it touches the at least one probe surface in a first contact position, in that a first tool coordinate of the tool in the direction of the probe axis is determined from the first contact position, in that the tool is moved parallel to the scanning direction from a second starting position, in which it does not touch the probe body and which is offset in a direction transverse, in particular perpendicular, to the scanning direction with respect to the first starting position,until it touches the at least one inclined sensing surface in a second contact position, and that from the second contact position a second tool coordinate is calculated in the direction of the probe body axis depending on the course of the at least one sensing surface and / or the at least one probe body surface on the one hand and the at least one inclined sensing surface on the other hand in the probe body coordinate system or in the coordinate system of the machine tool relative to each other.

[0041] As already explained, the proposed method makes it possible to determine a coordinate for referencing the tool in the probe body coordinate system or in the coordinate system of the machine tool in the direction of the probe body axis without the tool having to touch the probe body surface. Therefore, in particular, a movement of the tool toward the probe body surface is not required, but is optionally possible. In particular, the reference coordinate can be determined in the direction of the probe body axis even if, for example, the probe body surface cannot be touched by the tool due to spatial constraints on the machine tool.

[0042] It is advantageous if the probe body direction is selected so that it runs parallel to the probe direction, parallel to the probe body axis, or parallel to the inclined probe surface normal vector. This has the particular advantage that the tool can be moved toward the probe body in a probe body direction such that it can contact the probe body at a contact point or contact line.

[0043] For a particularly simple implementation of the method, it is advantageous if the scanning direction is selected so that it runs parallel to the scanning axis or parallel to the inclined scanning surface normal vector. In particular, the scanning direction can be selected so that it runs parallel to the working plane.

[0044] It is advantageous if the probe body is aligned in the machine tool's coordinate system such that the probe surface normal vector of the at least one probe surface defines an X-axis or a Z-axis of the machine tool's coordinate system, and the probe surface normal vector of the at least one probe surface defines a Y-axis of the machine tool's coordinate system. This specification enables, in particular, the simplest way to reference tools in the machine tool's coordinate system or in the probe body's coordinate system.

[0045] The above description therefore includes in particular the embodiments of measuring systems for machine tools, machine tools and methods for determining tool coordinates of a tool of a machine tool, defined below in the form of numbered sentences: 1. A measuring system (38) for a machine tool (10), in particular for a lathe (12), for automatically determining tool coordinates of a tool (26) of the machine tool (10), wherein the measuring system (38) comprises a touch sensor (40) which carries a touch body (42) defining a touch body coordinate system (44) and is designed to generate a touch signal upon contact of the touch body (42), in particular with the tool (26) of the machine tool (10), wherein the touch body (42) has at least one touch surface (72, 74, 76, 78) defining a touch surface normal vector (84, 86, 88, 90), wherein the touch surface normal vector (84, 86, 88, 90) runs perpendicular to the at least one touch surface (72, 74, 76, 78) and has a touch axis (92, 94), wherein the probe body (42) has at least one probe body surface (80, 82) defining a probe body surface normal vector (96, 98), wherein the probe body surface normal vector (96,98) extends perpendicular to the probe body surface (80, 82) and defines a probe body axis (100), wherein the probe surface normal vector (84, 88; 86, 90) and the probe body surface normal vector (96; 98) are linearly independent of one another, characterized in that the probe body (42) has at least one inclined probe surface (102, 104, 106, 108, 110, 112, 114, 116) defining an inclined probe surface normal vector (118), that the inclined probe surface normal vector extends perpendicular to the inclined probe surface (102, 104, 106, 108, 110, 112, 114, 116), that the inclined probe surface is arranged relative to the probe surface (72, 74, 76, 78) and relative to the Probe surface (80, 82) is inclined and that the inclined probe surface normal vector (118) is formed by vector addition from multiples of the probe surface normal vector (84, 86, 88, 90) and the probe surface normal vector (96, 98)., 2. Measuring system according to sentence 1, characterized in that the probe body coordinate system (44) is a Cartesian coordinate system. 3. Measuring system according to one of the preceding sentences, characterized in that the measuring system (38) comprises a positioning arm (46) which is arranged on a machine tool (10) or can be arranged on a machine tool (10), and in that the touch sensor (40) is arranged or formed on the positioning arm (46), in particular on a free end (48) of the positioning arm (46). 4. Measuring system according to sentence 3, characterized in that the probe body (42) is designed to be detachably connectable to the positioning arm (46). 5. Measuring system according to sentence 3 or 4, characterized in that the measuring system (38) comprises an interface device (70) for the unambiguous coupling of the probe body (42) to the positioning arm (46) in a measuring position. 6. Measuring system according to sentence 5, characterized in that the interface device (70) comprises first and second interface elements (64, 68) which are engaged with one another in the measuring position and which are disengaged in a cleaning position. 7. Measuring system according to one of the preceding sentences, characterized in that the at least one touch surface (72, 74, 76, 78) and the at least one touch body surface (80, 82) run perpendicular to each other. 8. Measuring system according to one of the preceding sentences, characterized in that the at least one sensing surface (72, 74, 76, 78) and the at least one inclined sensing surface (102, 104, 106, 108, 110, 112, 114, 116) enclose a first interior angle (122), that the at least one sensing body surface (80, 82) and the at least one inclined sensing surface (102, 104, 106, 108, 110, 112, 114, 116) enclose a second interior angle (124) and that an angle sum of the first interior angle (122) and the second interior angle (124) is 270°. 9. Measuring system according to sentence 8, characterized in that the first interior angle (122) and the second interior angle (124) have an identical value of 135°. 10. Measuring system according to one of the preceding sentences, characterized in that the probe body (42) has at least two probe surfaces (72, 74, 76, 78) whose probe surface normal vectors (84, 86, 88, 90) are linearly independent of one another. 11. Measuring system according to sentence 10, characterized in that the at least two touch surfaces (72, 74, 76, 78) run perpendicular to each other. 12. Measuring system according to sentence 10 or 11, characterized in that the probe body (42) has four probe surfaces (72, 74, 76, 78). 13. Measuring system according to sentence 12, characterized in that the four touch surfaces (72, 74, 76, 78) run parallel to each other in pairs. 14. Measuring system according to one of the preceding sentences, characterized in that the probe body (42) has two probe body surfaces (80, 82). 15. Measuring system according to sentence 14, characterized in that the two probe body surfaces (80, 82) run parallel to each other. 16. Measuring system according to one of the preceding sentences, characterized in that the at least one sensing surface (72, 74, 76, 78) and the at least one sensing body surface (80, 82) define a common edge (126) and that this edge (126) is chamfered by forming the at least one inclined sensing surface (102, 104, 106, 108, 110, 112, 114, 116). 17. Measuring system according to sentence 16, characterized in that the common edge (126) is chamfered over its entire length to form the at least one inclined scanning surface (102, 104, 106, 108, 110, 112, 114, 116). 18. Measuring system according to one of the preceding sentences, characterized in that the at least one inclined sensing surface (102, 104, 106, 108, 110, 112, 114, 116) and the at least one sensing surface (72, 74, 76, 78) define a first inclined sensing surface edge (128) and that the at least one inclined sensing surface (102, 104, 106, 108, 110, 112, 114, 116) and the at least one sensing body surface (80, 82) define a second inclined sensing surface edge (130). 19. Measuring system according to sentence 18, characterized in that the first inclined sensing surface edge (128) and the second inclined sensing surface edge (130) run parallel to each other. 20. Measuring system according to sentence 18 or 19, characterized in that the first and / or the second inclined touch surface edge (128, 130) run parallel to a touch surface normal vector (84, 86; 88, 90) of the touch body (42). 21. Measuring system according to one of the preceding sentences, characterized in that the probe surface normal vector (88, 90; 84, 86) defines an X-axis or a Z-axis of a coordinate system (22) of the machine tool (10) and that the probe body surface normal vector (96, 98) defines a Y-axis of the coordinate system (22) of the machine tool (10). 22. Measuring system according to one of the preceding sentences, characterized in that the coordinate system (22) of the machine tool (10) is a Cartesian coordinate system. 23. Measuring system according to one of the preceding sentences, characterized in that the probe body (42) is cuboid-shaped or substantially cuboid-shaped. 24. Measuring system according to one of the preceding sentences, characterized in that the at least one touch surface (72, 74, 76, 78) and / or the at least one inclined touch surface (102, 104, 106, 108, 110, 112, 114, 116) and / or the at least one touch body surface (80, 82) are rectangular, in particular square. 25. Measuring system according to one of the preceding sentences, characterized in that the measuring system (38) comprises a data processing device (34) for calculating a second coordinate value of the tool (26) in the direction of the probe body axis (100) from two first coordinate values ​​of the tool (26) in the direction of the probe axis (92, 94), which are measured when touching on the one hand the at least one probe surface (72, 74, 76, 78) and on the other hand the at least one inclined probe surface (102, 104, 106, 108, 110, 112, 114, 116). 26. Measuring system according to sentence 25, characterized in that the data processing device (34) and the touch sensor (40) are operatively connected for transmitting touch signals. 27. Measuring system according to sentence 25 or 26, characterized in that the data processing device (34) comprises a storage device (36) for storing probe body data which define surfaces of the probe body (42), in particular the at least one probe surface (72, 74, 76, 78) and the at least one probe body surface (80, 82). 28. Measuring system according to sentence 27, characterized in that the storage device (36) is designed to store the probe body data in the coordinate system (22) of the machine tool (10) or in the probe body coordinate system (44). 29. Machine tool (10), in particular a lathe (12), for machining a workpiece (16) with a tool (26), wherein the machine tool (10) defines a coordinate system (22) and comprises a measuring system (38) for automatically determining tool coordinates of a tool (26) of the machine tool (10), characterized in that the measuring system (38) is designed in the form of a measuring system (38) according to one of the preceding sentences. 30. Machine tool according to sentence 28, characterized in that the probe body (42) is arranged on the machine tool (10) such that the probe body coordinate system (44) defines the coordinate system (22) of the machine tool (10) or vice versa. 31. Method for determining tool coordinates of a tool (26) of a machine tool (10), in particular a lathe (12), with a measuring system (38), characterized in that a measuring system (38) according to one of the preceding sentences is provided as the measuring system (38), that for a first measurement the tool (26) is moved from a first starting position, in which it does not touch the probe body (42), in a scanning direction (132) which is not parallel to the probe body surface normal vector (96, 98), towards the probe body (42) until it touches the at least one probe surface (72, 74, 76, 78) in a first contact position, that from the first contact position a first tool coordinate of the tool (26) in the direction of the probe axis (92, 94) is determined, that the tool (26) is moved from a second starting position, in which it does not touch the probe body (42) and which is related to the first starting position in a direction (136) transverse,in particular perpendicular, offset to the scanning direction (132), is moved in a scanning direction (138) towards the scanning body (42) until it touches the at least one inclined scanning surface (102, 104, 106, 108, 110, 112, 114, 116) in a second contact position, and that from the second contact position a second tool coordinate in the direction of the scanning body axis (100) is calculated depending on the course of the at least one scanning surface (72, 74, 76, 78) and / or the at least one scanning body surface (80, 82) on the one hand and the at least one inclined scanning surface (102, 104, 106, 108, 110, 112, 114, 116) on the other hand in the scanning body coordinate system (44) or in the coordinate system (22) of the machine tool relative to each other., 32. Method according to sentence 31, characterized in that the probe body direction (138) is selected such that it runs parallel to the probe direction (132) or parallel to the probe body axis (100) or parallel to the oblique probe surface normal vector (118). 33. Method according to sentence 31 or 32, characterized in that the scanning direction (132) is selected such that it runs parallel to the scanning axis (92, 94) or parallel to the oblique scanning surface normal vector (118). 34. Method according to one of sentences 31 to 33, characterized in that the probe body (42) is aligned in the coordinate system (22) of the machine tool (10) such that the probe surface normal vector (88, 90; 84, 86) of the at least one probe surface (72, 74, 76, 78) defines an X-axis or a Z-axis of the coordinate system (22) of the machine tool (10) and that the probe body surface normal vector (84) of the at least one probe body surface (80, 82) defines a Y-axis of the coordinate system (22) of the machine tool (10).

[0046] The following description of preferred embodiments serves to provide further explanation in conjunction with the drawings. They show: Fig. 1: a schematic perspective view of an embodiment of a positioning arm with touch sensor and touch body; Fig. 2: an enlarged view of a free end of the positioning arm from Fig. 1 with touch sensor and touch body; Fig. 3: a perspective view of the probe body from the Fig. 1 and Fig. 2; Fig. 4: a view of the arrangement from Fig. 2 in the direction of arrow A; Fig. 5: a view of the arrangement from Fig. 2 in a direction analogous to the view from Fig. 4; Fig. 6: a perspective view of the probe body with interface element for detachable connection to the touch sensor; Fig. 7: a schematic representation of a machine tool; Fig. 8: a schematic representation of the surfaces on the probe body relevant for the measuring system; Fig. 9 to 12: a schematic representation of the referencing of a tool of a machine tool in a first scanning direction; Fig. 13 to 16: a schematic representation of the process of referencing a tool in a second scanning direction; Fig. 17 to 20: a schematic representation of a further process of referencing a tool; and Fig. 21 to 24: a schematic representation of a further process of referencing a tool.

[0047] In Fig. 7, an embodiment of a machine tool 10 is shown schematically, namely in the form of a lathe 12. It comprises a rotary spindle 14, with which a workpiece 16 can be rotated about a rotation axis 18. To drive the rotary spindle 14, a Fig. 7 schematically illustrated drive device 20.

[0048] The rotation axis 18 defines the Z-axis in a coordinate system 22 of the machine tool 10. An X-axis, which runs perpendicular to the Z-axis, together with the Z-axis, defines a working plane 24.

[0049] To machine the workpiece 16, a Fig. 7 schematically illustrated tool 26, which can be moved in the desired manner in the usual way with a tool drive device 28 in order to machine the workpiece 16 with a cutting edge 30.

[0050] A third axis of the coordinate system 22, hereinafter referred to as the Y-axis, runs perpendicular to the X-axis and the Z-axis. It is thus also perpendicular to the work plane 24.

[0051] The machine tool 10 further comprises a control and / or regulating device 22. Furthermore, the machine tool 10 can optionally comprise a data processing device 34 with a storage device 36 for storing data, in particular position coordinates of the tool 26 and design data of the workpiece 16, in order to bring the workpiece 16 into the desired shape by machining with the tool 26.

[0052] In alternative embodiments, the data processing device 34 and the storage device 36 can also be configured separately from the machine tool 10. Furthermore, they can also be configured separately from one another.

[0053] In order to reference the tool 26 in the coordinate system of the machine tool 10, the machine tool 26 comprises a measuring system 38 for automatically determining tool coordinates of the tool 26. The measuring system 38 comprises a probe sensor 40. This carries a probe body 42. The probe body 42 defines a probe body coordinate system 44.

[0054] The touch sensor 40 is designed to generate a touch signal when the touch body 42 touches the tool 26. The touch signal stops the movement of the tool 26, and the coordinates of the surface of the touch body 42 touched by the tool 26 are assigned to the tool 26 by means of the control and / or regulating device 32 or the data processing device 34. This allows the tool 26 to reference its exact position in the coordinate system 22. How this is done in detail will be explained in more detail below.

[0055] A positioning arm 46 is used to position the touch sensor 40 with the probe body 42 in the working space of the machine tool 10. The touch sensor 40 is arranged at a first free end 48. A first positioning element 52 is arranged or formed at a second free end 50 of the positioning arm, which is connected to a second interface element 54, which is arranged or formed on the machine tool 10, in a measuring position, as shown schematically in Fig. 7 is engaged.

[0056] The first and second interface elements 52 and 54 form components of a positioning arm interface device 56 for securing the positioning arm 46 in the measuring position to the machine tool 10 in a defined manner. The first and second interface elements 52 and 54 are engaged with each other. They can be disengaged so that the positioning arm 46 can be removed from the machine tool 10 in a removal position.

[0057] Fig. 1 schematically shows an embodiment of such a positioning arm 46 with a touch sensor 40 arranged at the first free end 48 and a first interface element 52 arranged at the second free end 50. The Fig. 1 positioning arm 46 separated from the machine tool 10 thus assumes the removal position.

[0058] Fig. Figure 2 shows the positioning arm 26 slightly enlarged in the area of ​​the first free end 48. The touch sensor 40 comprises a coupling pin 60 protruding relative to an end surface 58 of the positioning arm 46. This coupling pin 60 is inserted into a coupling receptacle 62 on a sleeve-shaped interface element 64 protruding from the touch body 42. The coupling pin 60 points in the direction of the X-axis. The interface element 64 protrudes from the touch body 42 in the direction of the negative X-axis.

[0059] Two fastening screws 66 serve to secure the first interface element 64 to the coupling pin 60, which forms a second interface element 68 of an interface device 70. The interface device 70 is designed in a manner not shown in detail such that the probe body 42 is uniquely coupled to the probe sensor 40 and thus also to the positioning arm 46 in the measuring position. This means that both a relative position in the direction of the X-axis and a rotational position about the X-axis are uniquely specified by the interface device 70 in the measuring position.

[0060] In the embodiment illustrated in the figures, the sensing body 42 is cuboid-shaped. It has three pairs of surfaces, each formed by two parallel surfaces: a first sensing surface 72 and a second sensing surface 74, a third sensing surface 76 and a fourth sensing surface 78, as well as a first sensing body surface 80 and a second sensing body surface 82.

[0061] As in Fig. 6 schematically shows the first sensing surface 72 facing the positive Z-axis, the second sensing surface 74 facing the negative Z-axis. The third sensing surface 76 facing the positive X-axis, the fourth sensing surface 78 facing the negative X-axis. The first sensing body surface 80 facing the positive Y-axis. The second sensing body surface 82 facing the negative Y-axis.

[0062] The probe body coordinate system 44 is formed in the form of a Cartesian coordinate system. The coordinate system 22 of the machine tool 10 is also formed in the form of a Cartesian coordinate system.

[0063] The touch surfaces 72 to 78 run perpendicular to the touch body surfaces 80 and 82. Furthermore, the touch surfaces 72 and 74 also run perpendicular to the touch surfaces 76 and 78.

[0064] Each of the four touch surfaces 72, 74, 76, and 78 defines a touch surface normal vector 84, 86, 88, and 90. The touch surface normal vectors 84 and 86 point in opposite directions. The touch surface normal vectors 88 and 90 also point in opposite directions. The touch surface normal vectors 84, 86, 88, and 90 each run perpendicular to the associated touch surface 72, 74, 76, and 78.

[0065] The probe surface normal vectors 84 and 86 define a first probe axis 92, which runs parallel to the Z-axis. The probe surface normal vectors 88 and 90 define a second probe axis 94, which runs parallel to the X-axis. Thus, the probe axes 92 and 94 also span the working plane 24.

[0066] The two probe surfaces 80 and 81 define first and second probe surface normal vectors 96 and 98. The probe surface normal vector 96 points in a direction parallel to the positive y-axis, and the second probe surface normal vector 98 points in a direction parallel to the negative y-axis. The probe surface normal vectors 96 and 98 run perpendicular to the associated probe surfaces 80 and 82, respectively.

[0067] The two probe surface normal vectors 96 and 98 define a probe axis 100 that runs parallel to the Y-axis.

[0068] The first touch surface normal vector 84, the third touch surface normal vector 88, and the first touch body surface normal vector 96 are linearly independent vectors in the mathematical sense. Likewise, the second touch surface normal vector 86, the fourth touch surface normal vector 90, and the second touch body surface normal vector 98 are linearly independent of each other in the mathematical sense.

[0069] In the embodiment shown in the figures, the probe body 42 further comprises eight inclined probe surfaces 102, 104, 106, 108, 110, 112, 114 and 116.

[0070] The beveled sensing surfaces 102, 104, 106 and 108 form chamfers or bevels of the edges between the first sensing body surface 80 and the third sensing surface 76, the first sensing body surface 80 and the first sensing surface 72, the first sensing body surface 80 and the fourth sensing surface 78 and the first sensing body surface 80 and the second sensing surface 74.

[0071] In a corresponding manner, the inclined sensing surfaces 110, 112, 114 and 116 form bevels or chamfers between the second sensing body surface 82 and the third sensing surface 76, the second sensing body surface 82 and the second sensing surface 74, the second sensing body surface 82 and the fourth sensing surface 78 and the second sensing body surface 82 and the first sensing surface 72.

[0072] The inclined tactile surfaces 102, 104, 106, 108, 110, 112, 114, and 116 are inclined relative to the respective tactile surface 72, 74, 76, 78 and relative to the tactile body surface 80 and 82, respectively. An inclined tactile surface normal vector 118, which runs perpendicular to the respective inclined tactile surface 102, 104, 106, 108, 110, 112, 114, and 116, is formed by vector addition from multiples of the respective tactile surface normal vectors 84, 86, 88, 90 and the associated tactile body surface normal vector 96 and 98, respectively.

[0073] The sensing body 42 is shaped such that the first and second sensing surfaces 72, 74 are essentially square. The third and fourth sensing surfaces 76 and 78, as well as the first and second sensing surfaces 80 and 82, are elongated rectangular in shape. The Z-axis forms the preferred axis of these surfaces.

[0074] In Fig. Figure 8 schematically illustrates a partial sectional view of the probe body 42. This sectional view shows the third probe surface 76, the first probe body surface 80 running perpendicular to it, and the first inclined probe surface 102 connecting them. Also shown are the third probe surface normal vector 88 and the first probe body surface normal vector 96. Also shown are the second probe axis 94, the probe body axis 100, and an inclined probe surface axis 120, which runs parallel to the inclined probe surface normal vector 118.

[0075] The representation in Fig. 8 can be applied analogously to all possible sectional views of the probe body 42 in the area of ​​the inclined contact surfaces 102, 104, 106, 108, 110, 112, 114 and 116. To understand the function of the measuring system 38, the arrangement of Fig. 8 is referred to.

[0076] The sensing surface 76 and the inclined sensing surface 102 enclose a first interior angle 122. The sensing body surface 80 and the inclined sensing surface 102 enclose a second interior angle 124. The sum of the two interior angles 122 and 124 is 270°. Accordingly, the first inclined sensing surface 102 is inclined by 45° relative to both the third sensing surface 76 and the first sensing body surface 88. In the illustrated embodiment, the first interior angle 122 and the second interior angle 124 have an identical value of 135°.

[0077] In Fig. 8 further shows a common edge 126 of the third tactile surface 76 and the first tactile body surface 80, which is chamfered by forming the inclined tactile surface 102 as already described.

[0078] The edge 126 is chamfered over its entire length to form the inclined touch surface 102. This design is provided for all inclined touch surfaces 102, 104, 106, 108, 110, 112, 114, and 116.

[0079] The inclined touch surface 102 and the third touch surface 76 define a first inclined touch surface edge 128. The first inclined touch surface 102 and the third touch surface 76 intersect along this first inclined touch surface edge 128.

[0080] The first inclined sensing surface 102 and the first sensing body surface 80 define a common second inclined sensing surface edge 130 along which they intersect.

[0081] The first beveled touch surface edge 128 and the second beveled touch surface edge 130 run parallel to each other.

[0082] The two inclined touch surface edges 128 and 130 also run parallel to the first and second touch surface normal vectors 84 and 86.

[0083] The measuring system 38 comprises the data processing device 34 of the machine tool 10. Alternatively, a separate data processing device can also be provided. It serves to calculate a second coordinate value of the tool 26 in the direction of the probe body axis 100 from two first coordinate values ​​of the tool 26 in the direction of one of the probe axes 92, 94, which are measured upon contact with one of the four probe surfaces 71, 74, 76, or 78, on the one hand, and one of the eight inclined probe surfaces 102, 104, 106, 108, 110, 112, 114, and 116, on the other hand.

[0084] The data processing device 34 and the touch sensor 40 are operatively connected to transmit touch signals as already mentioned above.

[0085] The method for determining tool coordinates of the tool 26 is described below in a first variant in connection with the Fig. 9 to 12 explained.

[0086] Fig. 9 shows a first starting position in which, for a first measurement, the tool 26 does not touch the probe body 42. From this first starting position, it is moved in the scanning direction 132, in this variant parallel to the second scanning axis 94, toward the probe body 42, specifically toward its third scanning surface 76.

[0087] In Fig. 10 schematically shows a first contact position in which the tool 26 touches the third contact surface 76. In the contact position, the touch sensor 40 detects the contact and sends a touch signal to the control and / or regulating device 32 or the data processing device 34. The movement of the tool 26 is stopped. The X coordinate of the third contact surface 76 is known in both the probe body coordinate system 44 and the coordinate system 22 of the machine tool 10. This can now be assigned as the X coordinate to the tool 26 or a tip 134 thereof.

[0088] In the next step, the tool 26 is moved back to the first starting position. This first starting position is in Fig. 11 is represented by the tool 26 shown in dashed lines. From this initial position, the tool 26 is displaced laterally in a transverse direction 136 transversely, namely perpendicularly, to the scanning direction 132. In this variant, the transverse direction 136 runs parallel to the Y-axis.

[0089] Based on the Fig. 11, the tool 26 is now moved in the probe body direction 138, which corresponds to the probe direction 132 or runs parallel to it, towards the probe body 42, until the tip 134 touches the first inclined probe surface 102 in a second contact position, as shown schematically in Fig. 12. Due to the bevel of the first beveled sensing surface 102, the tip 134 can be moved in the negative X-axis direction beyond the third sensing surface 26 by an amount Δx. A distance of the tip 134 in the second contact position from the first sensing body surface 80 is, as shown in Fig. 12 schematically shows Δy. The contact point with the inclined sensing surface 102 has a value for the X coordinate. Knowing the course of the first sensing body surface 80 in the sensing body coordinate system 44 or in the coordinate system 22 of the machine tool 10, as well as knowing the course of the first inclined sensing surface 102 relative to the third sensing surface 76 and the first sensing body surface 80, a Y value, thus the Y coordinate, of the contact point of the tip 134 and the first inclined sensing surface 102 can be calculated.

[0090] Using the described method, a Y coordinate of the tool 26 can be determined without the tool 26 touching either of the two probe surfaces 80 or 82. The movement of the tool 26 is also stopped upon reaching the second contact position, and the calculated Y value is assigned to the tip 134 of the tool 26 by the data processing device 34.

[0091] In the manner described, all other inclined touch surfaces 104, 106, 108, 110, 112, 114, and 116 can also be used to reference the tool 26 in the coordinate system 22 of the machine tool 10. The X-coordinates and Z-coordinates of the tool 26 can be determined directly by touching one of the four touch surfaces 72, 74, 76, or 78. A Y-coordinate for referencing the tool 26 can be determined mathematically by touching one of the eight inclined touch surfaces 102, 104, 106, 108, 110, 112, 114, and 116.

[0092] A comparison to that associated with the Fig. The procedure modified from the variant of the measuring method explained in sections 9 to 12 is shown schematically in the Fig. 13 to 16. Here, the probe body direction 138 does not run parallel to the second probe axis 94, but rather transversely to it, but in no case parallel to the probe body axis 100, and thus not parallel to the Y-axis.

[0093] Fig. 13 schematically shows a first starting position in which the tool 26 does not touch the probe body 42. The tool 26 is moved obliquely in the scanning direction 132 toward the third touch surface 76 until its tip 134 touches the third touch surface 76. As a result of the contact, the touch sensor 40 generates a touch signal, which is transmitted to the control and / or regulating device 32, whereupon the latter stops the movement 26 of the tool. The tip 134 of the tool 26 can now be assigned the X coordinate of the third touch surface 76.

[0094] In the next step, the tool 26 is moved back to the starting position, which is Fig. 15 is shown in dashed lines. From the first starting position, the tool 26 is moved transversely to the scanning direction 132, namely in the transverse direction 136, into a second starting position.

[0095] From the second starting position, the tool 26 is moved in the probe direction 138 toward the probe body 42 until the tip 134 touches the first inclined probe surface 102, which causes the probe sensor 40 to transmit a touch signal to the control and / or regulating device 32, which then stops the movement of the tool 26.

[0096] From the X-coordinate reduced by the value Δx and knowing the course of the first inclined sensing surface 102 relative to the third sensing surface 76 or the first sensing body surface 80, the difference Δy of the Y-coordinate of the tip 134 relative to the Y-coordinate of the first sensing body surface 80 can be easily calculated. The Y-value of the contact point of the tip 134 and the first inclined sensing surface 102 thus calculated is then assigned to the tool 26.

[0097] The probe body direction 138 can in particular be as shown schematically in the Fig. 13 and Fig. 15, it can be selected so that it runs perpendicular to the first inclined touch surface 102. The transverse direction 136 can then run in particular parallel to the first inclined touch surface 102.

[0098] A further variant for referencing the tool 26 in the coordinate system 22 of the machine tool 10 or in the probe body coordinate system 44 is described below in connection with the Fig. 17 to 20 explained.

[0099] In this variant, as already mentioned in connection with the Fig. 9 and Fig. 10, initially starting from a first starting position in which the tool 26 does not touch the probe body 42, the tool 26 is moved in the scanning direction 132 parallel to the second scanning axis 94 towards the probe body 42 until it touches the third scanning surface 76, as shown schematically in Fig. 18. The touch signal generated by the touch sensor 40 can be used to assign the X-coordinate of the third touch surface 76 to the tool 26.

[0100] In a next step, the tool 26 is inserted into a Fig. 19 solidly shown second starting position. This is related to the first starting position, which is determined by the Fig. 19, is offset by the transverse direction 136 transversely to the scanning direction 132. In this variant, the transverse direction 136 runs neither parallel to the third scanning surface 76 nor parallel to the first inclined scanning surface 102 nor parallel to the first scanning body surface 80. However, it is possible to decompose the transverse direction 136 into vectorial components parallel to the second scanning axis 94 and parallel to the scanning body axis 100. Thus, for example, starting from the first starting position, the tool 26 can first be moved by a movement in the direction of the positive Y-axis and then in the negative X-axis direction in order to move it as schematically shown in Fig. 19 shown.

[0101] From the second starting position, the tool 26 is moved in the probe direction 138 toward the probe body 42 until the tip 134 touches the first inclined probe surface 102, which causes the probe sensor 40 to transmit a touch signal to the control and / or regulating device 32, which then stops the movement of the tool 26.

[0102] Here, too, the difference Δy of the Y coordinate of the tip 134 relative to the Y coordinate of the first probe body surface 80 can be easily calculated from the X coordinate reduced by the value Δx and with knowledge of the course of the first inclined probe surface 102 relative to the third probe surface 76 or the first probe body surface 80. The Y value of the contact point of the tip 134 and the first inclined probe surface 102 thus calculated is then assigned to the tool 26.

[0103] The probe body direction 138 runs as shown schematically in Fig. 19 shown perpendicular to the first inclined touch surface 102.

[0104] The Fig. 21 to 24 schematically show a further sequence of referencing a tool 26 in the probe body coordinate system 44 or in the coordinate system 22 of the machine tool 10.

[0105] Fig. 21 schematically shows a first starting position in which the tool 26 does not touch the probe body 42. It is moved in the probe body direction 132 parallel to the second probe axis 94 perpendicularly toward the probe body 42, specifically toward its third probe surface 76.

[0106] Fig. Figure 22 schematically shows the contact between the tool 26 and the third touch surface 76. The touch signal generated by the touch sensor 40 upon contact is transmitted to the control and / or regulating device 32 or the data processing device 34. The determined X value of the contact point is assigned to the tool 26 as the X coordinate.

[0107] Fig. 23 shows schematically a second starting position of the tool 26. This second starting position is related to the first starting position in Fig. 21, which in Fig. 23 is schematically shown in dashed lines, offset by the transverse direction 136. The transverse direction 136 can be as schematically shown in Fig. 23 can be vectorially decomposed into a component in the direction of the Y-axis and a component in the direction of the X-axis, i.e. into the transverse direction component 136X in the X-direction and into the transverse direction component 136Y in the Y-direction.

[0108] Starting from the second starting position, the tool 26 in this variant is moved in the probe body direction 138, which runs parallel to the probe body axis 100, in the negative Y-axis direction towards the probe body 42 until the tip 134 touches the first inclined probe surface 102. This is shown schematically in Fig. 24 shown.

[0109] Here, too, the Y value of the contact point between tool 26 and first inclined sensing surface 102 of tool 26 can be determined from the course of the first inclined sensing surface relative to the first sensing body surface 80.

[0110] When following the procedure described in accordance with the Fig. 21 to 24, the tool 26 is moved into the second starting position in particular such that first a displacement movement parallel to the Y-axis in the positive direction thereof is carried out and then a displacement movement in the direction of the negative Y-axis is carried out. Since, before the tool 26 is moved into the second starting position, not only the X-coordinate of the third sensing surface 76 but also the course of the first inclined sensing surface 102 is known, the transverse direction component 136X in the X-direction can be selected such that the tip 134 can reliably touch the sensing body 42 in the region of the first inclined sensing surface 102 when the tool 26 is moved in the sensing body direction 138. In this exemplary embodiment, the sensing body direction 138 runs parallel to the transverse direction component 136Y.

[0111] The proposed measuring system 38 as well as the proposed measuring or referencing method for tools 26 of machine tools 10 not only enables the referencing of a position of the tool 26 in the coordinate system 22 of the machine tool 10 in the direction of the X-axis and the Z-axis, but also in the direction of the Y-axis, in particular in connection with the Fig. 9 to 24. This is made possible by the formation of the inclined sensing surfaces 102, 104, 106, 108, 110, 112, 114, and 116, as well as by knowledge of their course in the coordinate system 22 and the sensing body coordinate system 44, respectively. With the described method, it is not necessary to touch the sensing body surfaces 80 and 82 with the tool 26.

[0112] In conjunction with the figures, a probe body 42 with a total of eight inclined probe surfaces 102, 104, 106, 108, 110, 112, 114, and 116 was described. Depending on the tool 26 to be referenced and the design of the machine tool 10, a single inclined probe surface is generally sufficient to perform the referencing of the tool 26. In particular, it is alternatively conceivable to provide one, two, three, four, five, six, seven, or eight inclined probe surfaces. Any permutations of the eight described inclined probe surfaces 102, 104, 106, 108, 110, 112, 114, and 116 can be provided as possible inclined probe surfaces of a probe body 42, each depending on the intended number of inclined probe surfaces.

[0113] Depending on the specific design of the machine tool 10 and the tools 26, the shape of the positioning arm 46 can be adapted accordingly in order to position the probe body 42 in the working space of the machine tool 10 where it can be reliably contacted by the tool 26, namely on one or more of the four probe surfaces 72 to 78 and one or more of the eight inclined probe surfaces 102, 104, 106, 108, 110, 112, 114 and 116. List of reference symbols 10 Machine tool 12 Lathe 14 turning spindle 16 Workpiece 18 Rotation axis 20 Drive device 22 Coordinate system 24 working levels 26 tools 28 Tool drive device 30 cutting edges 32 Control and / or regulating device 34 Data processing facility 36 Storage device 38 measuring system 40 touch sensor 42 probe bodies 44 Probe coordinate system 46 Positioning arm 48 first free end 50 second free end 52 first interface element 54 second interface element 56 Positioning arm interface device 58 End face 60 coupling pin 62 Coupling recording 64 first interface element 66 Mounting axis 68 second interface element 70 Interface setup 72 first touch surface 74 second touch surface 76 third touch surface 78 fourth touch surface 80 first sensing body surface 82 second probe surface 84 first touch surface normal vector 86 second touch surface normal vector 88 third touch surface normal vector 90 fourth touch surface normal vector 92 first tactile axis 94 second sensing axis 96 first probe surface normal vector 98 second probe surface normal vector 100 Probe axis 102 first slanted key surface 104 second slanted keypad 106 third slanted key surface 108 fourth slanted key surface 110 fifth slanted key surface 112 sixth slanted key surface 114 seventh inclined touch surface 116 eighth slanted key surface 118 Inclined touch surface normal vector 120 Inclined keypad axis 122 first interior angle 124 second interior angle 126 edge 128 first beveled keypad edge 130 second beveled keypad edge 132 Scanning direction 134 lace 136 Transverse direction 136X Transverse component in X direction 136Y Transverse component in Y direction 138 Probe direction

Claims

[1] Measuring system (38) for a machine tool (10), in particular for a lathe (12), for automatically determining tool coordinates of a tool (26) of the machine tool (10), wherein the measuring system (38) comprises a touch sensor (40) which carries a touch body (42) defining a touch body coordinate system (44) and is designed to generate a touch signal upon contact of the touch body (42), in particular with the tool (26) of the machine tool (10), wherein the touch body (42) has at least one touch surface (72, 74, 76, 78) defining a touch surface normal vector (84, 86, 88, 90), wherein the touch surface normal vector (84, 86, 88, 90) runs perpendicular to the at least one touch surface (72, 74, 76, 78) and has a touch axis (92, 94), wherein the probe body (42) has at least one probe body surface (80, 82) defining a probe body surface normal vector (96, 98), wherein the probe body surface normal vector (96,98) extends perpendicular to the probe surface (80, 82) and defines a probe axis (100), wherein the probe surface normal vector (84, 88; 86, 90) and the probe surface normal vector (96; 98) are linearly independent of one another, , characterized by that the probe body (42) has at least one inclined probe surface (102, 104, 106, 108, 110, 112, 114, 116) defining an inclined probe surface normal vector (118), that the inclined probe surface normal vector runs perpendicular to the inclined probe surface (102, 104, 106, 108, 110, 112, 114, 116), that the inclined probe surface is inclined relative to the probe surface (72, 74, 76, 78) and relative to the probe body surface (80, 82), and that the inclined probe surface normal vector (118) is formed by vector addition from multiples of the probe surface normal vector (84, 86, 88, 90) and the probe body surface normal vector (96, 98). [2] Measuring system according to claim 1, characterized bythat the probe body coordinate system (44) is a Cartesian coordinate system. [3] Measuring system according to one of the preceding claims, characterized by that the measuring system (38) comprises a positioning arm (46) which is arranged on a machine tool (10) or can be arranged on a machine tool (10), and that the touch sensor (40) is arranged or formed on the positioning arm (46), in particular on a free end (48) of the positioning arm (46), wherein in particular a) the probe body (42) is designed to be detachably connectable to the positioning arm (46) and / or b) the measuring system (38) comprises an interface device (70) for the unambiguous coupling of the probe body (42) to the positioning arm (46) in a measuring position, wherein in particular the interface device (70) comprises first and second interface elements (64, 68) which are engaged with one another in the measuring position and which are disengaged in a cleaning position. [4] Measuring system according to one of the preceding claims, characterized by that the at least one touch surface (72, 74, 76, 78) and the at least one touch body surface (80, 82) run perpendicular to one another. [5] Measuring system according to one of the preceding claims, characterized bythat the at least one touch surface (72, 74, 76, 78) and the at least one inclined touch surface (102, 104, 106, 108, 110, 112, 114, 116) enclose a first interior angle (122), that the at least one touch body surface (80, 82) and the at least one inclined touch surface (102, 104, 106, 108, 110, 112, 114, 116) enclose a second interior angle (124) and that an angle sum of the first interior angle (122) and the second interior angle (124) is 270°, wherein in particular the first interior angle (122) and the second interior angle (124) have an identical value of 135°. [6] Measuring system according to one of the preceding claims, characterized by that the touch body (42) has at least two touch surfaces (72, 74, 76, 78) whose touch surface normal vectors (84, 86, 88, 90) are linearly independent of one another, wherein in particular a) the at least two touch surfaces (72, 74, 76, 78) are perpendicular to each other and / or b) the touch body (42) has four touch surfaces (72, 74, 76, 78), wherein in particular the four touch surfaces (72, 74, 76, 78) each run parallel to one another in pairs. [7] Measuring system according to one of the preceding claims, characterized by that the probe body (42) has two probe body surfaces (80, 82), wherein in particular the two probe body surfaces (80, 82) run parallel to one another. [8] Measuring system according to one of the preceding claims, characterized by that the at least one touch surface (72, 74, 76, 78) and the at least one touch body surface (80, 82) define a common edge (126) and that this edge (126) is chamfered by forming the at least one inclined touch surface (102, 104, 106, 108, 110, 112, 114, 116), wherein in particular the common edge (126) is chamfered over its entire length to form the at least one inclined touch surface (102, 104, 106, 108, 110, 112, 114, 116). [9] Measuring system according to one of the preceding claims, characterized by that the at least one inclined touch surface (102, 104, 106, 108, 110, 112, 114, 116) and the at least one touch surface (72, 74, 76, 78) define a first inclined touch surface edge (128) and that the at least one inclined touch surface (102, 104, 106, 108, 110, 112, 114, 116) and the at least one touch body surface (80, 82) define a second inclined touch surface edge (130), wherein in particular a) the first inclined touch surface edge (128) and the second inclined touch surface edge (130) run parallel to each other and / or b) the first and / or the second inclined touch surface edge (128, 130) run parallel to a touch surface normal vector (84, 86; 88, 90) of the touch body (42). [10] Measuring system according to one of the preceding claims, characterized by , that a) the probe surface normal vector (88, 90; 84, 86) defines an X-axis or a Z-axis of a coordinate system (22) of the machine tool (10) and that the probe surface normal vector (96, 98) defines a Y-axis of the coordinate system (22) of the machine tool (10) and / or b) the coordinate system (22) of the machine tool (10) is a Cartesian coordinate system. [11] Measuring system according to one of the preceding claims, characterized by that the probe body (42) is cuboid-shaped or substantially cuboid-shaped. [12] Measuring system according to one of the preceding claims, characterized by that the at least one touch surface (72, 74, 76, 78) and / or the at least one inclined touch surface (102, 104, 106, 108, 110, 112, 114, 116) and / or the at least one touch body surface (80, 82) are rectangular, in particular square. [13] Measuring system according to one of the preceding claims, characterized bythat the measuring system (38) comprises a data processing device (34) for calculating a second coordinate value of the tool (26) in the direction of the probe body axis (100) from two first coordinate values ​​of the tool (26) in the direction of the probe axis (92, 94), which are measured when touching on the one hand the at least one probe surface (72, 74, 76, 78) and on the other hand the at least one inclined probe surface (102, 104, 106, 108, 110, 112, 114, 116), wherein in particular the data processing device (34) a) and the touch sensor (40) are operatively connected to transmit touch signals and / or b) a storage device (36) for storing probe body data which define surfaces of the probe body (42), in particular the at least one probe surface (72, 74, 76, 78) and the at least one probe body surface (80, 82), wherein in particular the storage device (36) is designed to store the probe body data in the coordinate system (22) of the machine tool (10) or in the probe body coordinate system (44). [14] Machine tool (10), in particular a lathe (12), for machining a workpiece (16) with a tool (26), wherein the machine tool (10) defines a coordinate system (22) and comprises a measuring system (38) for automatically determining tool coordinates of a tool (26) of the machine tool (10), characterized by that the measuring system (38) is designed in the form of a measuring system (38) according to one of the preceding claims. [15] Machine tool according to claim 14, characterized bythat the probe body (42) is arranged on the machine tool (10) such that the probe body coordinate system (44) defines the coordinate system (22) of the machine tool (10) or vice versa. [16] Method for determining tool coordinates of a tool (26) of a machine tool (10), in particular a lathe (12), with a measuring system (38), characterized bythat a measuring system (38) according to one of claims 1 to 13 is provided as the measuring system (38), that for a first measurement the tool (26) is moved from a first starting position, in which it does not touch the probe body (42), in a scanning direction (132) which is not parallel to the probe body surface normal vector (96, 98), towards the probe body (42) until it touches the at least one probe surface (72, 74, 76, 78) in a first contact position, that from the first contact position a first tool coordinate of the tool (26) in the direction of the probe axis (92, 94) is determined, that the tool (26) is moved from a second starting position, in which it does not touch the probe body (42) and which is offset in a direction (136) transverse, in particular perpendicular, to the scanning direction (132) with respect to the first starting position, in a scanning direction (138) is moved towards the probe body (42) until it touches the at least one inclined probe surface (102, 104, 106, 108, 110,112, 114, 116) in a second contact position, and that from the second contact position a second tool coordinate in the direction of the probe body axis (100) is calculated depending on the course of the at least one probe surface (72, 74, 76, 78) and / or the at least one probe body surface (80, 82) on the one hand and the at least one inclined probe surface (102, 104, 106, 108, 110, 112, 114, 116) on the other hand in the probe body coordinate system (44) or in the coordinate system (22) of the machine tool relative to each other. [17] Method according to claim 16, characterized by , that a) the probe body direction (138) is selected such that it runs parallel to the probe direction (132) or parallel to the probe body axis (100) or parallel to the inclined probe surface normal vector (118) and / or b) the scanning direction (132) is selected such that it runs parallel to the scanning axis (92, 94) or parallel to the oblique scanning surface normal vector (118). [18] Method according to claim 16 or 17, characterized by that the probe body (42) is aligned in the coordinate system (22) of the machine tool (10) such that the probe surface normal vector (88, 90; 84, 86) of the at least one probe surface (72, 74, 76, 78) defines an X-axis or a Z-axis of the coordinate system (22) of the machine tool (10) and that the probe body surface normal vector (84) of the at least one probe body surface (80, 82) defines a Y-axis of the coordinate system (22) of the machine tool (10).

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