Measuring system and measuring method for measuring a tool

Abstract

In a measuring system for measuring tools by means of a measuring device (110) with which a plurality of insert modules (200) for arranging tools on the measuring device in defined positions are associated, an insert module comprises a tool receptacle for receiving a tool to be measured and a data carrier (175) for carrying module information data. The measuring device comprises a spindle unit mounted in a stationary part of the measuring device for rotation about a spindle axis and an insert-module receptacle for receiving an insert module (200) in a defined position. The measuring device comprises a control unit (190) which can be operated by means of an operating unit and a transmission system having a transmission path for automatically transmitting module information data between the data carrier (175) and the control unit (190). The control unit is configured, in an operating mode, for permanent monitoring of the insert module by reading out module information data at high frequency.

Description

[0001] Measuring system and measuring method for measuring a tool

[0002] FIELD OF APPLICATION AND STATE OF THE ART

[0003] The invention relates to a measuring system and a measuring method for measuring tools with the aid of a measuring device to which several insert modules for the position-defined arrangement of tools on the measuring device are assigned.

[0004] Measuring systems of the type discussed here are often part of a tool measuring and setting machine. A measuring device of the measuring system comprises components for holding a tool to be measured and components for measuring the held tool. The measuring device has a spindle unit that is mounted in a stationary part of the measuring device so that it can rotate about a spindle axis. Typically, a coordinate slide is attached to the base body, which supports the measuring system to be aligned to the tool. Nowadays, camera systems with connected image processing are commonly used as measuring systems.

[0005] In order to be able to measure and / or adjust many, possibly different, tools or tool types in a short space of time using such a measuring device, several insert modules for the position-defined arrangement of tools on the measuring device are assigned to a measuring device in generic measuring systems. The insert modules function as adapters to adapt the measuring device's mounting geometry to the respective tool type or its mounting geometry. For this purpose, an insert module holder for the position-defined mounting of an insert module is designed at the freely accessible end of the spindle unit. A tool holder, for example a hollow shank taper (HSK) or a steep taper (SK) tool holder, is located on an insert module.Using such insert modules enables highly flexible tool measurement and / or adjustment, as the measuring device can be quickly and easily adapted to the type of tool being measured by exchanging insert modules. Using this measuring device, a tool inserted into the insert module can be measured in different rotational positions.

[0006] When using such insert modules, the measuring device must be calibrated or referenced before the actual measuring process begins in order to establish a clear relationship between the measuring device's measuring coordinate system and the tool-side tool coordinate system. The measuring coordinate system describes, for example, the coordinate system of the coordinate slide. The tool coordinate system refers to a logical zero point of an insert module. Its position depends on the type of standardized tool holder in the insert module. The tool parameters (e.g., tool length or tool radius) should be referenced to this logical zero point during the measurement.

[0007] Since the logical zero point of the tool coordinate system is not accessible for measurement, an auxiliary zero point is attached to each insert module. This offset is determined by measuring the insert module and stored on the insert module in the form of module information data, allowing the user to use the information about the offset for later measurement.

[0008] In the past, there were often measurement errors that were due to operator errors, e.g. because the correct application module was not selected or because module information data was not correctly entered into the control unit.

[0009] To avoid the latter problems, patent application DE 101 24 275 A1 presents a method that provides for the automatic transmission of module information data from the insert module to the measuring device. This enables automatic identification of the insert module used, and the correct data assigned to the insert module, in particular the auxiliary coordinates for the auxiliary zero point, are automatically provided for further measurement and evaluation. The previously common manual data entry is thus eliminated as a potential source of error. This increases process reliability on the one hand, and makes the measuring procedure more user-friendly on the other. The content of DE 101 24 275 A1 is incorporated into this application by reference.

[0010] DE 101 24 275 A1 proposes various techniques for transmitting module information from the insert module to the measuring device. For example, inductive or radio transmission is mentioned. Alternatively, optical information transmission can be used, for example with the aid of a bar code on the insert module and a corresponding bar code reader on the measuring device. The data carriers on the insert module include semiconductor-based data carriers, e.g. data chips, which can be writable and electrically contacted or read out contactlessly, e.g. inductively. EP 1 586 413 A1 describes the transmission of module information using a data transmission camera. Automated data transmission from the insert module to the measuring device has proven successful many times in practice. In measuring systems of this type, a data carrier for carrying module information is also attached to the insert module.The measuring device includes a computer-based control unit that can be operated via a control unit. The measuring device includes a transmission system with a transmission link for the automatic transmission of module information data between the data storage device and the control unit.

[0011] It has been observed that despite the automation of data transfer, errors can occasionally occur when using insert modules, particularly for users who work highly productively and possibly with relatively small batch sizes. These errors are usually only noticed when a workpiece has been machined with a measured tool and the dimensions did not correspond to the specifications.

[0012] TASK AND SOLUTION

[0013] Against this background, the invention is based on the object of providing a measuring system and a measuring method for measuring tools, in which an automatic transmission of module information from an insert module to a measuring device is provided. In particular, this should make it possible to ensure or even further increase process reliability at low cost.

[0014] To achieve this object, the invention provides a measuring system having the features of claim 1 and a measuring method having the features of claim 10. Preferred developments are specified in the dependent claims. The wording of all claims is incorporated into the description by reference.

[0015] According to one aspect of the invention, a measuring system for measuring tools is provided. In the measuring method, the measurement is carried out using a measuring device that is a component of the measuring system. The measuring device is assigned several insert modules that are part of the measuring system and serve for the position-defined arrangement of tools on the measuring device. An insert module has a tool holder for holding a tool to be measured. The tool holder can, for example, have a conical section and be designed such that a tool or a tool holder with a hollow shank taper, a steep taper, or a Morse taper can be received therein in a defined position. The measuring device has a spindle unit that is mounted in a stationary part of the measuring device such that it can be rotated about a spindle axis. A rotary drive can be provided for this purpose, but this is not mandatory.Manual spindle rotation is also possible. The spindle unit can be mounted, for example, in the base body of the device or in a bearing unit permanently mounted on the device. The spindle axis is preferably aligned vertically, but this is not mandatory. The spindle unit has an insert module holder at its freely accessible end for the position-defined mounting of an insert module. An insert module functions like an adapter, allowing a specific tool to be mounted on the spindle unit of the measuring device in such a way that the tool can later be measured in different rotational positions or from different directions, if necessary.

[0016] Preferably, the inserted tool is retracted into the tool holder of the insert module using an integrated pulling device to ensure a secure fit. This automatically pulls the insert module into the insert module holder, ensuring a secure fit.

[0017] The measuring device is computer-controlled and has a computer-based control unit that can be operated via an operating unit. In order for the measuring device to perform a desired measuring operation, a geometric relationship must be established between the tool coordinate system and the machine coordinate system. This requires, among other things, information about the specific module being used, since the relationship between the coordinate systems can vary depending on the module. To enable automatic information transfer, an insert module has a data carrier for carrying module information data. The measuring system has a transmission system with a transmission link for the automatic transmission of module information data between the data carrier and the control unit.

[0018] According to a formulation of the claimed invention, the control unit is configured in an operating mode for permanent monitoring of the deployment module by high-frequency reading of module information data.

[0019] This enables a measuring method in which the insert module is continuously monitored automatically and controlled by the control unit by high-frequency reading of module information data from the data carrier attached to the inserted insert module. This aspect of the claimed invention is based, among other things, on the finding that process reliability can be improved if the corresponding module information data for identifying the insert module is transmitted to the control unit of the measuring device not only once in temporal connection with the insertion of the insert module. Rather, process reliability can be increased if module information data is repeatedly read out and further processed at short intervals or at high frequency even after the initial information transmission, thus realizing virtually uninterrupted monitoring of inserted insert modules.This is referred to here as permanent monitoring, even if there are short pauses between the individual readout operations. The module information data therefore does not have to be read out continuously. A sufficiently high-frequency readout, i.e. repeated readout with regular sampling, is sufficient. For example, the control unit can be configured so that module information data is read out at cycle times of the order of one second or less, e.g. at intervals in the tenths of a second range or in the range of a few milliseconds, for example every 10 ms. The readout can begin at a start time and last until an end time. The start time can be, for example, the time the insert module is inserted and the end time the time the system is removed.

[0020] Regarding the purpose of such continuous monitoring and testing of the respective insert module in use, the following considerations are relevant. Each insert module, i.e., each adapter, has its own coordinate zero point, which can be described using the auxiliary coordinates. From a manufacturing perspective, it is practically impossible to manufacture all insert modules, which should have nominally identical geometric and connection dimensions, to exactly the same coordinate zero point. Thus, even between nominally identical insert modules, there are small differences in geometry that directly impact the measurement results determined when using the selected insert module.Using the measuring system without permanent monitoring and checking of the inserted module carries the risk that after a change of an insert module, this change will not be acknowledged in the software or otherwise noted, resulting in incorrect measurement results.

[0021] Reasons for incorrect measurement results can include, for example, an operator forgetting to select an insert module change in the software. It is also possible that an operator confuses two nominally identical insert modules without informing the software. It is also possible that an operator leaves their workstation at the measuring device (e.g., to take a break) and another operator temporarily uses the freed-up measuring and setting device to quickly perform another measurement process during the break. In this case, the operator may physically reset the measuring device but forget to acknowledge the change in the software.Finally, it is also possible that an insert module is damaged and a replacement insert module is ordered, which is simply re-inserted and reused, even though this results in a different offset between the machine coordinate system and the tool coordinate system.

[0022] Sources of error of this kind and other circumstances that endanger process safety can be systematically avoided if the permanent monitoring of the insert module described here is carried out.

[0023] According to a further development, a special configuration of the control unit makes it possible to automatically detect a change in module status. For this purpose, module information data read out consecutively is automatically compared with one another in a comparison operation. Depending on the result of the comparison, an action can then be initiated to react to the change in the status of the module used. If the comparison shows no difference, then nothing has changed. A significant difference in the values ​​on which the comparison is based is interpreted as a change in module status. The module status changes, for example, when one module is replaced with another. The action resulting from the comparison can, for example, be that an operator is prompted by the software to acknowledge the module change.The action can also consist of automatically reading the new module information and processing it further for measurement purposes. Removing the insert module is also recognized as a status change. Although this generally means that proper measurement is no longer possible, it is still detected and, for example, an operator message appears.

[0024] Special features of the components in the transmission path can support quasi-permanent monitoring and ensure particularly reliable process implementation. According to a further development, the transmission path comprises a first pair of transmitters for transmitting signals between the insert module and a component of the spindle unit, and a second pair of transmitters for transmitting signals between the spindle unit and the stationary part of the measuring device. The module information data is encoded in the signals. There is a separate pair of transmitters for each interface in the transmission path. The first interface is the interface between the replaceable insert module and the spindle unit, which is part of the stationary measuring device.The second interface is located within the measuring system between the spindle unit, which rotates around the spindle axis, and a component in the stationary part of the measuring system—i.e., between a movable component (spindle unit) and a stationary component. At this interface, too, a transmission must be ensured that functions smoothly and without interruptions, regardless of the operating state of the measuring system and the rotational position of the spindle unit, in order to enable continuous monitoring.

[0025] According to a further development, the first pair of transmitters is designed for contactless or touchless transmission. The first pair of transmitters can operate, for example, inductively, capacitively, or wirelessly. Contactless transmission, i.e., transmission without physical contact between the transmission elements or transmitters of the transmitter pair, appears advantageous at this interface, since the transmission contact between an insertable module and the spindle is interrupted each time one insert module is removed and reestablished each time another insert module is inserted.If an insert module is inserted into the insert module holder in the correct rotational position, the communicating components of the transmitter pair maintain their relative arrangement to one another, so that the conditions for contactless transmission in the area of ​​this interface remain stable until the insert module is replaced.

[0026] In contrast, it is preferably provided that the second pair of transmitters is designed for contact-based transmission. This transmission takes place at the interface between the rotatably mounted spindle unit and the stationary part of the measuring device. The transmission should function virtually error-free and without interruptions, even if the spindle unit rotates or has been rotated relative to the stationary part. While the second pair of transmitters could also operate according to a contactless principle, for example, inductively or capacitively or wirelessly, contact-based transmission has proven to be significantly more robust and reliable at this interface, particularly for ensuring continuous transmission.

[0027] According to a further development, the second pair of transmitters comprises a slip ring arrangement. A slip ring arrangement is an electromechanical assembly designed to ensure electrical power transmission and / or electrical signal transmission between counter-rotating components. The transmission contact is ensured in the form of a sliding contact between a movable contact element and a stationary annular contact element. It has proven advantageous if the slip ring arrangement has a contact arrangement on the stationary part with several annular contact elements rotating concentrically to the spindle axis, while the contact elements in transmission contact are mounted opposite one another on the spindle unit.The contact elements can, for example, be electrically conductive brushes or spring-loaded sliding shoes made of suitable, electrically conductive contact material.

[0028] In preferred embodiments, the slip ring arrangement is designed as an axial slip ring arrangement, which in this context means that the contact elements of the interacting sides are located opposite each other in the axial direction of the spindle unit. This simplifies assembly. This arrangement also requires relatively little space and can therefore be accommodated even in complex installation environments. Alternative slip ring arrangements in which the cooperating slip ring contacts are located opposite each other in the radial direction are also possible.

[0029] It is possible for the module information data required for the application module to be stored once on the data carrier and subsequently no longer be deleted or modified. In this case, it would be sufficient to design the transmission path unidirectionally, so that only module information data or corresponding signals are transmitted from the data carrier to the control unit. In preferred embodiments, the data carrier is designed as a writable data carrier, and the transmission path is designed as a bidirectional transmission path. In this case, it is also possible to modify the information content stored in the data carrier after the original configuration of the data carrier within the measuring device by storing new data and / or by changing stored data.Communication can therefore be bidirectional, allowing both initial writing to the data storage device and, if necessary, modifying the information content during system runtime. This allows qualified personnel to modify values ​​stored on the data storage device, for example, if the values ​​for the coordinate origin on the insert module have changed due to special circumstances, such as damage to the adapter zero point balls or after reworking the insert module.

[0030] In preferred embodiments, components and methods from the field of RFID technology (RFID = radio-frequency identification) are used. For this purpose, the data carrier comprises an RFID transponder containing the module information in coded form. An RFID reader for reading the module information can be arranged on the spindle unit side, i.e., on the other side of the first transmitter pair. In a bidirectional first transmitter pair, an RFID read / write device can be arranged on the spindle side. This device creates a magnetic or electromagnetic field for data transmission, which supplies the passive RFID transponder with energy.

[0031] In a preferred embodiment of a measuring system, standardized components of an RFID identification system based on RFID transmission are particularly advantageously provided at the interface between the insert module and the spindle unit. These components are otherwise used in the technical environment of modern manufacturing to uniquely identify and track objects and products. For example, components of a commercial identification solution called BIS from the manufacturer Balluff can be used for this interface. The data, in particular the module information data, can then be transmitted between the RFID transponder and the read / write head (reader) and forwarded to the controller via a specially adapted evaluation unit. Accordingly, an evaluation unit belonging to the commercially available system can also be used here for the purpose of module identification.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Further advantages and aspects of the invention emerge from the claims and from the description of embodiments of the invention, which are explained below with reference to the figures.

[0034] Fig. 1 shows a schematic side view of an embodiment of a tool measuring and setting device with a measuring device;

[0035] Fig. 2 shows a longitudinal section through the spindle unit with inserted insert module;

[0036] Fig. 3 shows schematic components of the transmission path.

[0037] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The schematic side view in Fig. 1 shows components of an embodiment of a measuring system 100 according to the invention for vertical tool measurement and adjustment. The measuring system comprises a freely mountable measuring device 110, also referred to as measuring device 110, as well as a plurality of insert modules 200 assigned to the measuring device, which serve to attach the tools to be measured to the measuring device or to the measuring device. The measuring device has a stationary base body 120, which has on its upper side 122 devices for receiving a tool to be measured (see also Fig. 2). The devices include a spindle unit 140, which is rotatably mounted about a vertical spindle axis 145 by means of a bearing 127. The rolling bearing rings of the bearing are fastened on the one hand to the outside of the spindle unit 140 and on the other hand to the inside of a bearing unit 125, which is firmly mounted on the upper side 122 of the base body 120.The spindle unit can be rotated to any number of different positions using a computer-controlled rotary drive (not shown). Manual rotation is also possible.

[0039] The spindle unit 140 has an insert module holder 150 at its upper end for the position-defined reception of an interchangeable insert module 200. The insert module holder 150 has an upwardly widening conical section 152 directly on the input side, which mates with a conical section on the insert module and ensures centering and coaxial alignment of the inserted insert module in the insert module holder 150.

[0040] An insert module 200 has a predominantly conical tool holder 210 for receiving a tool 300 to be measured. Depending on the shape of the tool shank, the tool holder 210 can be designed, for example, as a hollow shank taper (HSK) or a steep taper (SK) tool holder.

[0041] The base body 120 also supports a horizontal slide (not shown), on which a column 160 is movable along a horizontal X-axis by means of computer-controlled motors. On its side facing the receiving devices, the column 160 carries a vertical slide, which is movable along a vertical Z-axis by means of another computer-controlled motor.

[0042] A C-shaped optics carrier 165 is attached to the vertical slide. It carries an illumination unit on one leg and a measuring camera 166 on the opposite leg. This measuring camera is an industrial camera (area scan camera, matrix camera) connected to an image evaluation device. The measuring camera, which serves as an optical measurement system for the tool, can be moved in the X and Z directions to bring a recorded tool into the image field of the measuring camera.

[0043] The entire system is computer-controlled. For this purpose, the drives for the horizontal and vertical displacement of the measuring camera 165, as well as the rotation of the spindle unit 140, are connected to a microprocessor-equipped control unit 190, which can be operated via an operating unit 195 equipped with a screen and keyboard (and / or touchscreen). The computer-assisted control unit has access to memory containing programs that, for example, control the measuring process. A portion of the image captured by the measuring camera, for example, a section of a tool cutting edge, can be displayed on the screen, along with all data relevant to the operator in a suitable format (numeric, graphic, etc.).

[0044] When using adapters in the form of insert modules, the measuring device must be calibrated or referenced before the actual measuring process begins in order to establish a clear relationship between the measuring device's measuring coordinate system and the tool-side tool coordinate system. The tool coordinate system refers to a logical zero point (NP) of an insert module. Its position depends on the type of standardized tool holder in the insert module. The tool parameters (e.g., tool length or tool radius) should be referenced to this logical zero point during the measurement.

[0045] Since the logical zero point of the tool coordinate system is not accessible for measurement, an auxiliary zero point HP is attached to each insert module. This can be implemented, for example, using a calibration edge or calibration sphere and can be attached, for example, in the upper edge area of ​​the insert module. The auxiliary zero point has a defined offset in the radial direction and in the longitudinal direction compared to the logical zero point NP, which offset can be described using auxiliary coordinates, i.e. difference values ​​between the logical zero point and the auxiliary zero point in the radial and longitudinal directions. These difference values ​​are determined by measuring the insert module. This measurement of the insert module and the recording of the auxiliary coordinates are usually carried out once by the manufacturer of the insert module so that the user can later use the auxiliary coordinates specific to the insert module for measurement.

[0046] An annular collar 212 is formed on the insert module, which, when the insert module is inserted, rests on the front side of the spindle unit 140 and thereby determines the position in the Z direction. A data carrier 175 in the form of an RFID chip, which carries module information data, is fastened to a radially open groove 203 in the annular collar at the edge of the insert module. The module information data includes, among other things, data that describes the offset between the logical zero point NP and the auxiliary zero point HP of the tool-internal tool coordinate system. The measuring device 110 comprises a transmission system for the automatic transmission of module information data between an insert module 200 inserted into the spindle unit or the data carrier 175 attached thereto, and the control unit 190 of the measuring device. Components of the transmission system are shown schematically in Fig. 3.

[0047] The transmission path between the data carrier 175 on the insert module and the control unit 190 runs through two interfaces, each of which is attached to a pair of transmitters, each with two communicating transmitter elements. A first transmitter pair 170 is used to transmit signals between the data carrier on the insert module and the spindle unit. On the insert module side, the data carrier (RFID chip) 175 acts as a transmitter element, which on the spindle unit side interacts with an RFID read / write head 178 as the second transmitter element of the first transmitter pair 170. In the example, the RFID read / write head is mounted in a sliding block, which serves to insert the inserted insert module 200 in the correct rotational position into the spindle-side insert module receptacle. The data carrier is attached in the corresponding groove 203 on the insert module 200.

[0048] The second transmitter pair 180 ensures the transmission of signals and energy between the spindle unit 140 and a machine-fixed component of the bearing unit 125. The second transmitter pair 180 comprises a slip ring arrangement whose transmitter elements 185, 182 are located opposite one another in the axial direction, i.e., in the direction of the spindle axis. The spindle-side transmitter element of the second transmitter pair is a contact ring 185 of the slip ring arrangement. The contact ring comprises four circular contact conductor tracks arranged coaxially to one another and radially spaced from one another. These contact conductor tracks are arranged on the underside of an element rotating with the spindle unit. A groove 126 is formed in the bearing unit 125 outside the rolling bearing rings of the bearing 127. A contact block 182, which forms the stationary transmitter element, is mounted in this groove.The contact block 182 has four radially offset sliding contacts, which are electrically connected to an evaluation unit of the RFID system integrated into the control unit and each contact one of the contact rings. The slip ring arrangement ensures that, regardless of the rotational position of the spindle unit, a contact-based transmission of data, signals, and energy is always ensured at this interface. A reversed arrangement of the contact block and contact ring is also possible.

[0049] In one operating mode, the control unit 190 is configured to continuously monitor the insert module inserted into the spindle unit by reading module information data from the data carrier 175 at high sampling rates via the transmission path and processing it in the evaluation unit. This continuous monitoring ensures that every change relevant to the measurement in the area of ​​the insert module or the insert module holder is registered promptly or practically immediately and taken into account in the further control process. This arrangement ensures that the flow of energy and data over the transmission path is always uninterrupted, even in harsh working environments, such as in a factory hall. The contact-based transmission of signals and power in the area of ​​the slip ring arrangement contributes significantly to this.Although the advantages of a possible contactless transmission (e.g. freedom from wear) are omitted at this interface, it results in increased process reliability, especially in harsh working environments.

[0050] A method for measuring a tool that can be carried out using the measuring system includes measuring the insert modules prior to the actual measurement in order to determine, among other things, the auxiliary coordinates that describe the offset in the radial and axial directions of the auxiliary zero point HP relative to the logical zero point NP. Corresponding module information data is then stored in readable form on the data carrier 175. The module information data can contain additional data, such as a unique module identification number, a serial number, information about the type of tool holder, the date of manufacture, the last calibration date, etc. The auxiliary coordinates and other module-specific data can also be stored outside the data carrier in a memory accessible to the measuring device.For example, it is also possible to later read out only the module identification number from the deployed module and, based on this, access the auxiliary coordinates or corresponding data stored at another location.

[0051] When the insert module to be measured is later selected for a measuring insert and inserted into the spindle unit or the insert module holder there, the data carrier 175 attached to the bottom of the radially open anti-rotation groove 203 is automatically in the correct position relative to the read / write head 178 of the RFID system mounted in the sliding block, so that contactless data transmission can take place at this point.

[0052] A wired transmission path for data and power leads from the read / write head to the spindle-side of the slip-ring arrangement 180, from where the signals containing the information are transmitted to the stationary side of the slip-ring arrangement via an electrically conductive contact. From there, a cable leads to the evaluation unit, which in the example is integrated into the control unit 190. As soon as the insert module is inserted and the control unit is set to monitoring mode, the module information data is read out and transmitted to the control unit. Using the transmitted data, the measuring device can be calibrated using the auxiliary zero point, e.g., by moving a crosshair of the optical measuring system to the calibration edge with the auxiliary zero point HP and the operator confirming the precise setting of the crosshair on the control unit.This establishes a computer-based connection between the measuring coordinate system and the tool coordinate system. Typically, only then is the tool to be measured inserted into the tool holder and measured in a conventional manner using the optical measuring system. This can include determining the tool length (Z value) and / or a tool radius (X value) and / or other tool parameters. The measured values ​​obtained can then be used computer-aided with the aid of the auxiliary coordinates to determine the tool parameters relative to the tool's internal logical zero point and output them to an output unit, such as a screen.

[0053] Although the required calibration can be performed with the first data transmission, in one operating mode of the control unit the module information continues to be read continuously from the data carrier at a high sampling rate (e.g. at intervals of the order of 10 ms (milliseconds) or less).

[0054] If the insert module is removed and replaced with another insert module, but an operator forgets to acknowledge this change via the control unit, it was previously possible for the measuring system to continue operating after the last calibration, even though the inserted insert module had a different geometry and therefore different auxiliary coordinates. In this case, incorrect measurements could result. Such errors are systematically avoided with this system of continuous module monitoring. Since the control unit reads module information at high sampling rates, a change of insert module not acknowledged by the operator on the control unit would always be automatically detected, as the read module information data would change.Thus, a new calibration would be carried out automatically after the next insert module was inserted, so that the measurement results then determined on the tool would also be correct within the scope of the basic measurement accuracy of the measuring device.

[0055] To automatically determine whether any changes have occurred to the module being used, consecutively read module information data are automatically compared with each other, and special processes may be initiated depending on the result of the comparison. The comparison operation does not need to be performed after each reading. Experience has shown that such comparisons are sufficient if they are performed only at longer intervals, for example, with at least one minute between consecutive comparison operations. This places minimal strain on the control unit's computing capacity, while simultaneously significantly increasing process reliability.

[0056] In the illustrated embodiment of the measuring device, the data carrier 175, the read / write head 178, and the RFID evaluation unit are standardized components of a commercial RFID identification system. Thus, a commercially available evaluation unit can be used to evaluate the module information data. The measuring and setting device or the measuring device can also be used as a device for writing data to data carriers on insert modules. For this purpose, the insert module can be measured using the measuring device in order to then write the data required for subsequent measuring applications, for example, the data on the auxiliary coordinates, into the data carrier. This eliminates the need for a separate measuring device for measuring the insert module.

Claims

Patent claims 1. A measuring system (100) for measuring tools using a measuring device (110) to which a plurality of insert modules (200) for the position-defined arrangement of tools on the measuring device are assigned, wherein an insert module (200) has a tool holder (210) for holding a tool (300) to be measured and a data carrier (175) for carrying module information data; the measuring device (110) has a spindle unit (140) which is rotatably mounted about a spindle axis (145) in a stationary part of the measuring device and has an insert module holder (150) for the position-defined holding of an insert module (200);the measuring device has a control unit (190) which can be operated via an operating unit (195) and a transmission system with a transmission path for the automatic transmission of module information data is provided between the data carrier (175) and the control unit (190), characterized in that the control unit is configured in an operating mode for permanent monitoring of the insert module by high-frequency reading of module information data; 2. Measuring system according to claim 1, characterized in that the control unit (190) is configured to read out the module information data at a clock rate of one second or less continuously from a start time to an end time, wherein preferably the start time is at the time of insertion and the end time is at the time of removal or shutdown of the system.

3. Measuring system according to claim 1 or 2, characterized in that the control unit (190) is configured to automatically detect a module status change, wherein module information data read out successively in time are automatically compared with one another in a comparison operation and an action is initiated depending on a result of the comparison.

4. Measuring system according to one of the preceding claims, characterized in that the transmission path comprises a first pair of transmitters (170) for transmitting signals between the insert module (200) and a component of the spindle unit and a second pair of transmitters (180) for transmitting signals between the spindle unit (140) and the stationary part of the measuring device (110).

5. Measuring system according to claim 4, characterized in that the first pair of transmitters (170) is designed for contactless transmission, in particular for inductive signal transmission.

6. Measuring system according to claim 4 or 5, characterized in that the second transmitter pair (180) is designed for contact-based transmission.

7. Measuring system according to claim 6, characterized in that the second pair of transmitters (180) has a slip ring arrangement, wherein preferably the slip ring arrangement on the spindle unit has a contact arrangement (185) with several annular contact elements rotating concentrically to the spindle axis, and contact elements (182) in transmission contact therewith, in particular electrically conductive brushes or spring-loaded sliding shoes, are mounted opposite one another on the stationary part of the measuring device and / or in that the slip ring arrangement is designed as an axial slip ring arrangement such that the contact elements of the interacting sides are opposite one another in the axial direction of the spindle unit (140).

8. Measuring system according to one of the preceding claims, characterized in that the data carrier (175) is designed as a writable data carrier and / or that the transmission path is designed as a bidirectionally usable transmission path.

9. Measuring system according to one of the preceding claims, characterized in that the data carrier (175) contains an RFID transponder for storing module information data and an RFID reader or an RFID read / write device is arranged on the spindle unit side.

10. Method for measuring a tool with the aid of a measuring device which has a control unit which can be operated via an operating unit and a spindle unit which is rotatable about a spindle axis and which has an insert module holder for the position-defined reception of an insert module, wherein an insert module has a tool holder for receiving a tool to be measured and a data carrier for carrying module information data which is generated by measuring of the deployment module include certain data on auxiliary coordinates and / or identification data for determining the auxiliary coordinates, the method comprising the following steps: - Selecting an insert module with data carrier that matches the tool; - Inserting the insert module into the insert module holder of the spindle unit; - Automatic transfer of module information data from the data carrier of the insert module to the measuring device before starting a measurement; - Calibration of the measuring device using the data on the auxiliary coordinates; - Inserting a tool into the tool holder; - Measuring the tool, characterized by permanent monitoring of the insert module inserted into the insert module holder by high-frequency reading of module information data.

11. The method according to claim 10, characterized in that the module information data are read out at a clock rate of 10 ms or less continuously from a start time to an end time, wherein preferably the start time is at the time of insertion and the end time is at the time of removal or shutdown of the system.

12. Method according to claim 10 or 11, characterized by automatic detection of a module status change, wherein module information data read out successively in time are compared with one another in a comparison operation and an action is initiated depending on a result of the comparison, in particular a request to an operator to acknowledge a module status change.

13. Method according to one of claims 10 to 12, characterized in that a transmission of signals along a transmission path takes place via a first interface between the insert module and a component of the spindle unit and a second interface between the spindle unit and the stationary part of the measuring device, wherein the transmission at the first interface is preferably contactless and at the second interface is contact-based, in particular via sliding contacts.

14. Method according to one of claims 10 to 13, characterized in that the data carrier is designed as a writable data carrier and the transmission path is used bidirectionally.

15. Use of components of an RFID identification system based on RFID transmission in a measuring device for measuring a tool, wherein an RFID transponder is used as a data carrier on an insert module, wherein module-specific module information data is stored in the data carrier; an RFID read / write head is used to read the data carrier and to write to the data carrier; module information data read from the data carrier are evaluated by an evaluation unit of the RFID identification system by means of an evaluation operation, and a control of the measuring device depending on results of the Evaluation operation is carried out.

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