Runout monitoring module and runout monitoring method for a tool rotating during operation

Abstract

An apparatus and method for monitoring the concentricity of a rotating tool during operation is described. The monitoring module comprises a tool interface for holding the tool and a tool holding interface for insertion into a tool holder. The monitoring module has a sensor unit, the axis of rotation of the monitoring module passing through the sensor unit. When the monitoring module rotates with the tool / tool ​​holder, the sensor unit detects a variable representative of an acceleration in a plane perpendicular to the axis of rotation of the monitoring module. A computing device of the monitoring module receives the variable representative of the acceleration recorded by the sensor unit, determines from this a total acceleration, compares the total acceleration with a threshold value, and determines that a concentricity error of the rotating tool, the monitoring module and / or the tool holder exists if the total acceleration is greater than the threshold value. A communication device of the monitoring module is connected to the computing device and transmits a signal to the machine tool / machine tool indicating whether there is a concentricity error or not.

Description

[Technical field]

[0001] Described herein is a concentricity monitoring module for a tool rotating during operation, a concentricity monitoring tool holder module, and a concentricity monitoring tool module. Further described are a machine tool / machine tool and a concentricity monitoring signal interface in operative communication with the concentricity monitoring module / concentricity monitoring tool mount module / concentricity monitoring tool module for monitoring the concentricity of the tool rotating during operation. Also described is a method for monitoring the concentricity of a tool rotating on a machine tool / machine tool, possibly performed by a concentricity monitoring module / concentricity monitoring tool holder module / concentricity monitoring tool module in communication with the machine tool / machine tool and / or the concentricity monitoring signal interface. The computer program product includes commands for causing the execution of process steps of a concentricity monitoring process. [Background technology]

[0002] An individual monitoring module is described for monitoring the concentricity of a tool rotating during operation. The tool is attached to a workpiece processing machine ne. The workpiece processing machine ne can be, for example, a (numerically controlled) machine tool (NC machine), a (multi-axis) machining center, a (multi-axis) milling machine, a flexible production cell, etc. In the following, the terms machine tool and machining center are also used for such machines.

[0003] This type of machine tool has a (main) axis into which the tools used in machining the workpiece, such as drills, milling cutters, etc., or the workpiece itself, are inserted. The axes can be in a fixed position or can be moved in the working area of ​​the machine tool in three orthogonal directions: X-, Y- and Z-directions. The axes can also be driven to rotate about the X-, Y- and Z-axes. In modern multi-task machines, it is often necessary to change tools during the machining of one workpiece. This is usually done by automatic tool changing, whereby a tool in the axis is exchanged for another tool in the tool magazine of the machine tool. During the tool change, the clamping device of the axis for holding the tool is exposed in the working area of ​​the machine. The same applies to the tool and the pre-mounted tool holder. As a result of chips and other impurities, deposits can accumulate on the clamping device of the axis and / or on the tool. In modern machine tools, the clamping device is usually designed as a taper interface, in particular a steep taper (SK) or a hollow shank taper (HSK) is used for the insertion of the tool. For example, if chips accumulate on the taper interface and / or HSK / SK during a tool change, the face contact / full retraction of the tool or its holder is no longer guaranteed, since the chips are caught between the taper interface and the holder. When the tool rotates with the shaft, a kind of wobble occurs, which results from imbalance due to lack of face contact / full retraction. If the wobble exceeds an acceptable level, the tool is considered to have a concentricity error. If the concentricity error goes unnoticed and no measures are taken, radial runout occurs in the rotating tool during workpiece machining, which results in inaccurate machining results and leads to poor surface quality and imbalance of the tool. Furthermore, concentricity errors put a strain on the tool itself, since they lead to increased wear and, ultimately, damage to the tool (including tool breakage). Concentricity errors can also occur if the tool and shaft are cleaned during a tool change, for example by supplying lubricating oil (cooling) or compressed air. Another reason for concentricity errors can be damage to the shaft itself.Therefore, it is important to quickly detect and accurately evaluate concentricity errors during operation of a rotary tool to ensure satisfactory machining results and a stable machining environment.

[0004] One method of detecting imperfect face contact of a tool on a machine tool shaft is to monitor the face contact using compressed air. Compressed air is applied to the area of ​​the machine tool's tapered interface so that if there is a defect in the facing system, the compressed air escapes between the shaft and the tool holder. By detecting this loss of pressure, a fault in the facing system is identified.

[0005] The Planko sensor system from OTT-JAKOB Spanntechnik GmbH, 87663 Lengenwang, Germany, measures the flatness of the tool of the machine tool via several ceramic sensors (resonators). The system is based on a compact passive electronic assembly consisting of a resonator, a cable and a connector, which is integrated into the axis nose. The flatness is measured by a continuous scanning of the resonator during rotation. In the read head, the current measurement result is compared with a predefined reference value stored in the internal memory. In case of deviation from the reference value, the measurement data is recorded via a comparator signal and transferred to the machine control system. In addition, there are at least some measuring systems integrated into the axis of the machine tool to monitor the facing system, which for example utilize force sensors, electromagnetic signals or laser light for the evaluation. In this connection, reference is also made, for example, to DE 102013201328 A1, DE 102018201427 A1, DE 10351347 A1, EP 3360642 A1, DE 102013 100975 A1 and EP 3581328 A1.

[0006] Laser measuring systems such as the LC50-DIGILOG from Blum-NovoteSt GmbH, 88287 Glucklaut, Germany, offer another option for monitoring the concentricity errors of rotating tools. The system detects concentricity errors of rotating tools, which are caused, for example, by contamination of the contact surface of the tool holder. Specific tool data is required for each tool and the measurement depends on the intended measuring point. The learning cycle first determines the basic concentricity error, which represents the difference between the longest and shortest cutting edge of the tool. Afterwards, a statement can be made about the concentricity error caused by contamination of the contact surface by measuring the cylindrical shank compared to its effect on the cutting edge to determine whether the currently measured concentricity error is greater or smaller than the stored basic concentricity error. The calculation is carried out by the NC program, whereby, among other things, the radial change of the longest cutting edge is taken into account as a wear value.

[0007] There are also intelligent tools for monitoring different process variables during machining. For example, in WO 2021 / 029404, the vibrations of a rotatable tool are measured by a number of acceleration sensors mounted on the tool shank symmetrically with respect to the tool's axis of rotation. Similarly, according to WO 2021 / 029 099, the vibrations are determined from signals from acceleration sensors and strain gauges mounted on the outside of the shank (for example of a turning or milling tool). WO 2019 / 122 375 describes, for example, a sensor module for a rotating tool holder of a machining tool to enable reliable detection of operating or system states in real time. For this, a sensor module including sensors for detecting the application of forces, temperature and accelerations (vibrations) is advantageously arranged in the tool holder at the axis of rotation, and the coolant flow is directed by design around this position. Such a positioning of the sensor module helps to minimize imbalances and simplify the insertion of the sensor module. The measurement signal is preferably transmitted wirelessly via a transmitter and an antenna to a receiver of the machine tool. A control device in the machine tool allows ad-hoc reactions to unstable conditions that have not yet stabilized. This is achieved by adapting machining parameters such as feed rates, speeds, etc. in real time, which adaptation is performed as a function of process conditions such as vibrations or forces on the tool. Tool systems for monitoring process variables are also disclosed in WO 2021 / 033 670, EP 2103379, US 10828740, US 10828739, EP 3808503, US 20210,26 322 and JP 5089342.

[0008] Such tool systems are conventionally powered, for example by batteries. However, some tool systems have devices for generating energy in the sense of energy harvesting, in order to supply the tool system itself, including the integrated electronics. For example, EP 3539717 A1 describes a machining tool with a power generation unit. A first part is fixedly connected to the body of the machining tool and a second part is movably connected to the body. When a fluid flows through the second part, the relative movement with the first part generates electrical energy. EP 2112461 A1 describes a measurement probe with a current generator, in which a flywheel is rotatably connected to the measurement probe. The rotor of the current generator has a permanent magnet and is connected to the flywheel, and a stator with an induction winding is mounted in the housing of the probe. When speeding up the rotational movement of the probe housing, the flywheel does not immediately follow the movement of the housing due to its large moment of inertia. Such a difference in movement converts the kinetic energy into electrical energy, as long as it exists. A freewheel is attached to the flywheel. The flywheel follows the rotation of the housing in a first rotational direction, but can only rotate freely in a second rotational direction opposite to the first rotational direction, so that electrical energy is generated. Further tool systems with the principle of energy harvesting are also disclosed in DE 102016223199 A1, US 2015 / 0125230 A1, EP 1742011 A1 and Taiwanese Patent I491463 A1.

[0009] Although the above-mentioned devices and processes for monitoring the concentricity of tools operate according to different detection principles, there are ways to improve the reliability and speed of detection in facing systems, especially with respect to tools for which concentricity is monitored. There is also room for improvement in terms of reducing the system costs.

[0010] For example, in the case of the above-mentioned monitoring of flat surfaces using compressed air, if the flat surface is defective, the pressure does not remain constant and a lot of air escapes over time. Monitoring using compressed air therefore only gives limited results. Furthermore, this system cannot detect imperfect flat surfaces if chips are deposited directly on the air outlet of the flat surface and block this air outlet. The Planko sensor system of OTT-JAKOB Spanntechnik GmbH, 87663 Lengenwang, Germany, has to be integrated in a complex manner into the shaft nose, which leads to high system costs. Furthermore, with this sensor system, the exact surface contact is determined by interrogating several ceramic sensors. In this process, in particular scraped and / or broken aluminum chips can adhere to the ceramic sensors. This can lead to a complete failure of the sensor system, which makes it impossible to recognize concentricity errors and therefore requires a time-consuming and costly exchange of the sensors. This also involves a complex integration, even if the force sensor is integrated into the shaft nose, as in EP 3 360 342 A1, and therefore high system costs. Furthermore, data acquisition and evaluation are complicated in these systems.

[0011] In concentricity monitoring devices operating in conjunction with laser measurement systems, determining concentricity is generally time consuming since it requires accurate positioning of the shaft within the measurement chamber or at the measurement point, despite the relatively long measurement times.

[0012] Currently, tools equipped with various sensors, e.g. temperature, force and acceleration sensors, are available on the market, which are used to record process parameters such as vibrations or cutting forces. However, none of these tools are able to detect clamping errors and there is no concentricity monitoring integrated into rotary tools yet. EP 2208017 A1 relates to a technique for adjusting the transmission power of a transmitting / receiving device in a machine position measurement system, which allows for robust and time-critical data transmission and fast connection establishment with low energy consumption. A first transmission power message is transmitted at a first transmission power, a second transmission power message is transmitted at a second transmission power, and if a transmission power confirmation message is received in response to the transmitted first transmission power message, the second transmission power is less than the first transmission power, and if a transmission power confirmation message is not received in response to the transmitted first transmission power message, the second transmission power is more than the first transmission power. The transmission power message is used to determine whether wireless communication between the transmitting / receiving device and the base station is possible with the current transmission power. Depending on the transmission situation over the air interface, i.e. if interference with other signals occurs, the transmission power of the transceiver is readjusted. In this way, a lower transmission power limit can be determined in order to avoid permanent transmission with excessive transmission power. This saves the energy of the transceiver. The transceiver transmits a transmission power message to the base station connected to the transceiver. After transmitting the transmission power message, the transceiver waits to receive a transmission power confirmation message. If the transmission power message is received by the base station connected to the transceiver, the base station transmits a transmission power confirmation message. Depending on the reception of the transmission power confirmation message, the transceiver knows whether a radio connection between the transceiver and the base station is possible or not. Depending on this information, the transceiver can increase or decrease the transmission power of subsequent transmission power messages.

[0013] After the second transmission power message, a third transmission power message may be transmitted at a third transmission power. If the transmission power of the second transmission power message is less than the transmission power of the first transmission power message and a transmission power confirmation message for the second transmission power message is received, the third transmission power is less than the second transmission power. If the transmission power of the second transmission power message is less than the transmission power of the first transmission power message and a transmission power confirmation message for the second transmission power message is not received, the third transmission power is more than the second transmission power. If the transmission power of the second transmission power message is more than the transmission power of the first transmission power message and a transmission power confirmation message is received in response to the second transmission power message, the third transmission power is equal to the second transmission power. If the transmission power of the second transmission power message is more than the transmission power of the first transmission power message and a transmission power confirmation message is not received in response to the second transmission power message, the third transmission power is more than the second transmission power. Summary of the Invention [Problem to be solved by the invention]

[0014] The objective of the solution presented here is to provide a methodology and an apparatus for monitoring (during operation) the concentricity of a rotary tool. [Means for solving the problem]

[0015] One of these devices is a machine-tool-independent, tool-integrated runout monitoring module, which is able to determine the runout error (or basic data) during rotation and, if necessary, transmit one or more corresponding status and / or measurement signals to a (runout monitoring) signal interface or to the machine tool control, in particular via a communication interface. The device and method improve existing solutions with regard to accuracy and speed of surface contact detection (and subsequent concentricity check) and are quick, simple and cheap to manufacture (even significantly cheaper compared to shaft-integrated systems). Easy integration into existing machine tools and easy combination with available tools or tool systems are also possible. This allows task-specific tools with concentricity monitoring to be assembled on demand with little effort.

[0016] According to a first aspect, this problem can be solved by a concentricity monitoring module for a tool which rotates during operation. The concentricity monitoring module comprises a tool interface which is configured to receive the rotating tool and a tool mounting interface which is configured in particular for insertion into a tool mount of a machine tool or a machining centre. The concentricity monitoring module further comprises a sensor unit which is assigned to the concentricity monitoring module such that the axis of rotation of the concentricity monitoring module passes through it and which is configured to detect variables in a plane which is oriented essentially perpendicular to the axis of rotation of the concentricity monitoring module when the concentricity monitoring module rotates, in particular together with said tool and / or tool holder which rotates. A computing device of the concentricity monitoring module , receive values ​​representative of the acceleration recorded by the sensor unit, determine an overall acceleration based on the recorded values ​​representative of the acceleration, compare during detection of the quantity representative of the acceleration the total acceleration with a threshold value dependent on the rotation speed of the runout monitoring module, and determine that a concentricity error of the rotating tool, the concentricity monitoring module and / or the tool holder is present if the total acceleration is greater than the threshold. A communication device of the concentricity monitoring module is communicatively connected to the computing device and is configured to send a signal to the machine tool / machine tool mix of whether there is a concentricity error of the rotating tool, the concentricity monitoring module and / or the tool holder.

[0017] The tool interface can be, for example, an ABS holder (ABS system) or an ABS adapter (ABS connection) into which a rotating tool or a corresponding ABS adapter of a rotating tool can be inserted. This ABS system can be, for example, the ABS system made by Ceratizit SA. Alternatively, the tool interface can be equipped with a collet holder into which a rotating tool can be inserted. Finally, the tool interface can be stably and concentrically connected to the rotating tool in any other suitable way.

[0018] Likewise, the tool holder interface can be designed, for example, as an ABS adapter for insertion into a tool holder designed as an ABS holder. This tool holder can be pre-assembled in the machine tool / machine tool, or can be inserted into the machine tool together with the concentricity monitoring module between the concentricity monitoring module and the shaft. Alternatively, the tool holder interface can be stably and concentrically connected to the tool holder in any other suitable manner.

[0019] The concentricity monitoring module establishes a customizable connection with concentricity monitoring between the machine tool axis and the rotating tool, thus providing a modular concentricity monitoring module structure suitable for all common machine tool interfaces such as SK, SK-FC, BT, BT-FC, HSK-A, PSC and HSK-E, thus allowing a combination of different tools with different axial contact surfaces to machine the workpiece, thus achieving maximum flexibility without compromising the concentricity monitoring function.

[0020] A second aspect relates to a concentricity monitoring tool holder module for a tool rotating during operation, the concentricity monitoring tool holder module comprising a tool interface configured to receive a rotating tool and a tool holder (WZGA) configured to be inserted into an axis of a machine tool or a machining center. The concentricity monitoring tool holder module also comprises a sensor unit associated with the concentricity monitoring tool mounting module such that the axis of rotation of the concentricity monitoring tool mounting module extends and configured to detect, via the monitoring tool mounting module, a variable in a plane oriented substantially perpendicular to the axis of concentric rotation when the monitoring tool mounting module rotates, in particular together with the rotating tool and / or axis. A computing device of the concentricity monitoring tool holder module is configured to receive values ​​representative of the acceleration detected by the sensor unit, determine an overall acceleration based on the recorded values ​​representative of the acceleration, compare the total acceleration (atot) during acquisition of the quantity representative of the acceleration with a threshold value dependent on the rotation speed of the concentricity monitoring tool holder module, and determine that a concentricity error of the rotating tool and / or tool holder is present if the total acceleration (atot) is greater than the threshold value (SW). A communication device of the concentricity monitoring tool holder module is communicatively connected to the computing device and configured to send a signal to the machine tool / machine tool set of whether there is a concentricity error of the tool and / or tool holder.

[0021] The tool interface can be, for example, an ABS holder (ABS system) or an ABS adapter (ABS connection) into which a rotating tool or a corresponding ABS adapter of a rotating tool can be inserted. Alternatively, the tool interface can be equipped with a collet holder into which a rotating tool can be inserted.

[0022] The tool holder can be designed as an ABS holder, in particular as HSK or SK for inserting a concentricity monitoring tool holder module into the axis of a machine tool / machine tool.

[0023] The concentricity monitoring tool holder module can therefore consist of a sensor unit, a computing device and a communication device, which are accommodated in a central housing that is permanently connected to the tool holder. The concentricity monitoring tool holder module, which establishes a connection between the shaft and the rotating tool, provides the option to flexibly use different tools for machining the workpiece without losing the concentricity monitoring functionality.

[0024] A third aspect relates to a concentricity monitoring tool module, comprising a tool rotating during operation and a tool holder configured to be inserted into an axis of a machine tool or a machining center. The concentricity monitoring tool module also comprises a sensor unit, assigned to the concentricity monitoring tool module such that the axis of rotation of the concentricity monitoring tool module extends and assigned to detect a variable in a plane oriented substantially perpendicular to the axis of rotation of the concentricity monitoring tool module, in particular when the concentricity monitoring tool module rotates with the axis. A computing device of the concentricity monitoring tool module is arranged to receive values ​​representative of the acceleration detected by the sensor unit, to determine a total acceleration based on the recorded values ​​representative of the acceleration, to compare the total acceleration during the detection of the quantity representative of the acceleration with a threshold value that depends on the rotation speed of the concentricity monitoring tool module, and to determine that a concentricity error of the concentricity monitoring tool module exists when the total acceleration is greater than the threshold value. A communication device of the concentricity monitoring tool module is communicatively connected to the computing device and is configured to transmit a signal to the machine tool / machine tool of whether there is a concentricity error of the concentricity monitoring tool module or not.

[0025] The tool holder provides the mechanical interface between the rotating tool and the axis of the machine tool. The tool holder can be designed as an ABS holder, specifically an HSK or SK, which is used to insert a concentricity monitoring tool module into the axis of the machine tool / machine tool.

[0026] The concentricity monitoring tool module, which establishes the connection between the shaft and the rotating tool, can be manufactured as a unit, for example by the tool manufacturer, which eliminates the need for detachable interfaces such as the tool interface and the tool mounting interface according to the first aspect (and thus possible sources of contamination or build-up preventing accurate axial runout). This means that different tools can be provided with further improved concentricity monitoring capabilities, which are especially required for high precision applications.

[0027] When describing features of a "module" or a "monitoring module" below, these features may refer in particular to the concentricity monitoring module according to the first aspect, the concentricity monitoring tool holder module according to the second aspect and the concentricity monitoring tool module according to the third aspect, respectively. This is especially true when describing components such as a computing device, a sensor unit and a communication device comprised in the module according to the first aspect, the module according to the second aspect and the module according to the third aspect.

[0028] The computing device of the monitoring module can be included in a data processing device, which can also include an (intermediate) memory. In this way, the variables recorded by the sensor unit can be processed and temporarily stored in the data processing device or can be transmitted as data to the machine tool or to a concentricity monitoring signal interface. The data processing device, the sensor unit and the communication device (also the data transmission device) can be composed of electronic devices.

[0029] A digital IO signal (IO: OK or NOK: not OK) can be sent to the machine tool as a 1-bit signal when signaling whether the rotating tool has a concentricity error or not. Wireless transmission is possible, as are other communications between the monitoring module and the machine tool.

[0030] The sensor unit may comprise an acceleration sensor, which may be a piezoelectric acceleration sensor or may be based on a spring-mass system. Alternatively, a strain gauge may be used or a magnetic induction acceleration sensor may be used.

[0031] The acceleration sensor of the sensor unit can be, for example, a two-axis acceleration sensor, which is set up to measure acceleration in mutually orthogonal x- and y-directions. Alternatively, the acceleration sensor can in particular be two one-axis acceleration sensors of identical construction, for example arranged one above or next to the other and offset by 90° with respect to the sensitive axis (the inertial axis along which acceleration is measured), to measure acceleration in mutually orthogonal x- and y-directions. Alternatively, a three-axis acceleration sensor can be used to additionally record a process variable, such as vibration in the z-direction, which is orthogonal to the x- and y-directions.

[0032] The rotation axis of the monitoring module can pass through the body of the sensor unit at least approximately centrally, but does not have to pass through the acceleration sensor itself (although this is of course also possible). In other words, the sensor unit can be arranged in the monitoring module such that at least one inertial axis of the sensor unit is arranged at least approximately coaxially, in particular within a tolerance distance, with respect to the rotation axis of the monitoring module. This inertial axis can be the z-axis of the acceleration sensor even in the case of a two-axis acceleration sensor set up to measure acceleration in the x-direction and acceleration in the y-direction. In other words, this inertial axis does not have to coincide with the sensitive axis of the sensor unit (this also applies when the sensor unit comprises two one-axis acceleration sensors), which also applies to a three-axis acceleration sensor.

[0033] When using a two- or three-axis acceleration sensor, the two- or three-axis acceleration sensor comprises two or three measuring chips (with two or three different measuring directions) arranged with a minimum distance from each other. In order to obtain perfectly coincident acceleration values ​​close to zero, the sensor unit can be arranged on the monitoring module such that the orientation of the x measuring chip (measuring acceleration in the x direction) of the two- or three-axis acceleration sensor coincides with the yz-plane of the monitoring module and the y measuring chip (measuring acceleration in the y direction) of the two- or three-axis acceleration sensor coincides with the xz-plane of the monitoring module. In these variants, the inertial axis of the sensor unit, which is arranged at least approximately coaxially with the rotation axis of the monitoring module, in particular within a tolerable distance, is not the sensing axis of the measuring chip itself but the inertial axis of the z-axis of the body of the sensor unit.

[0034] By arranging the x-measuring chip and the y-measuring chip spatially separated, for example, a circular recess can extend through the sensor unit body along the inertial z-axis of the sensor unit body between the individual measuring chips.

[0035] In particular, the tolerance distance may be the radial (normal) distance from the axis of rotation of the monitoring module to the axis of inertia of the sensor unit and may range up to ±10 μm.

[0036] The inertial axis of the sensor unit being arranged at least approximately coaxially with respect to the rotation axis of the monitoring module means that an angular error (angular offset) of up to ±3° can occur between the inertial axis and the rotation axis.

[0037] In principle, the sensor unit can be arranged on the monitoring module in such a way that, in the event of a certain concentricity error, the position or orientation of the sensor unit changes at a known speed and in a known position, in particular due to a prior calibration, which indicates a failure of the planar contact of the tool holder (axis) of the machine tool with the monitoring module.

[0038] In particular, the sensor unit can be mounted on the monitoring module in such a way that the acceleration sensor is positioned as ideally as possible on the axis of rotation. This makes it possible to detect a variable representative of acceleration in the xy plane perpendicular to the axis of rotation (oriented in the z direction), e.g. a tilt and / or a lateral offset of the axis of rotation of the monitoring module caused by a faulty chip or a defective axis is detected as a change in acceleration in the (radial) xy plane. This change can preferably be related to a reference acceleration value determined in the course of a calibration process and thus to a "learned" reference system.

[0039] The positioning of the sensor unit can therefore be selected so that the acceleration sensor provides the largest possible deviation with the smallest possible tilt / eccentricity, thereby ensuring that the acceleration sensor detects concentricity errors that increase with increasing tilt (of the monitoring module relative to the rotation axis of the spindle or machine tool axis).

[0040] An acceleration sensor positioned precisely on the rotation axis of the monitoring module measures zero centrifugal acceleration even at relatively high speeds (radial distance r = 0 of the acceleration sensor from the rotation axis of the monitoring module). On the other hand, an offset from the center (r ≠ 0), for example due to clamping errors, generates a centrifugal acceleration on the acceleration sensor during rotation. In order to monitor the rotation of the tool, this centrifugal acceleration in particular in the xy plane (rotation plane) can be recorded as a variable representing the acceleration. A selected position of the acceleration sensor of the monitoring module, which is aligned as centrally as possible with respect to the tool holder of the machine tool when the monitoring module is inserted in the machine tool, can in particular ensure that the maximum change in the centrifugal forces acting on the acceleration sensor is given with the minimum concentricity error.

[0041] Regarding the centrifugal acceleration a,

number

number

number

[0042] The speed is included in the calculation of the square of the centrifugal acceleration. It is therefore important for the detection (detection of centrifugal acceleration) to know exactly the speed at which the detection is performed. This (test) speed has, for example, an essentially constant value throughout the detection or lies within a tolerance of up to ±10% of the specified speed value.

[0043] The sensor unit can be used to record the variables representative of acceleration within a certain evaluation time (also called recording time). The evaluation time can be a time window of a few seconds, for example 0.1 to 5 seconds. However, the evaluation time can also be a certain number of revolutions (of the monitoring module and therefore of the tool in the machine tool) during which the variables representative of acceleration are recorded. The evaluation time can be, for example, 4, 8, 16, 32 or 64 revolutions, but the disclosure is not limited thereto. This "evaluation time" also applies to all other variables detected by the monitoring module, unless otherwise specified in the relevant place.

[0044] Since the direction of the central offset (eccentricity) is not known before detection, the acceleration values ​​in the x- and y-direction (in the plane of rotation) can be detected, in particular by a 2-axis or 3-axis acceleration sensor, and calculated to form a (total) acceleration vector. In this way, the total acceleration value can be determined from the values ​​representative of the acceleration and recorded by the sensor unit as follows:

number

[0045] The calculation of the total acceleration based on the variables recorded by the sensor unit, as well as the other calculations described in the context of this disclosure, can in each case be performed based on the acceleration values ​​output by the acceleration sensor, but can also be calculated using the (digital) transducer values ​​(raw data) generated by a transducer associated with the acceleration sensor.

[0046] The data processing unit (computing unit) of the monitoring module can be connected to the sensor unit via a digital or analog communication interface. For example, a digital SPI or I / O between the sensor unit and the data processing unit. 2 A C interface is possible. It is also conceivable to provide analog acceleration values ​​at the output of the sensor unit and to record these in a data processing device using an analog-to-digital converter (ADC).

[0047] A fourth aspect relates to a machine tool or machining centre comprising an axis that rotates about an axis of rotation during operation of the machine tool / machine centre and that is configured to receive and operatively communicate with the tool mounting interface of the concentricity monitoring module of the first aspect, the tool fixture of the concentricity monitoring toolholder module of the second aspect and / or the concentricity monitoring tool module of the third aspect, and a communication device of the machine tool / machine centre arranged to receive signals from the communication device of the runout monitoring module of the first aspect, the communication device of the runout monitoring toolholder module of the second aspect and / or the communication device of the runout monitoring tool module of the third aspect. The control device of the machine tool / machine tool is connected to the communication device of the machine tool / machine tool and is configured to receive values ​​representative of acceleration detected by the sensor units of the runout monitoring module of the first aspect, the sensor units of the runout monitoring tool holder module of the second aspect and / or the sensor units of the runout monitoring tool module of the third aspect, determine a total acceleration based on the recorded values ​​representative of acceleration, and during detection of the quantity representative of acceleration, compare the total acceleration with a threshold value dependent on the rotational speed of the axis, and determine that a concentricity error of the runout monitoring module of the first aspect, the runout monitoring tool holder module of the second aspect and / or the runout monitoring tool module of the third aspect exists if the total acceleration is greater than the threshold value.

[0048] In particular, the axes of the machine tool / machine tool set can be configured to interact with tool holders such as steep tapers or hollow shank tapers.

[0049] The variables representative of the acceleration received by the monitoring module can be transmitted as processed data to the control system of the machine tool via a communication device, which can also perform the function of a data transmission device and be part of the interface on the machine tool side. Alternatively, the variables representative of the acceleration can be transmitted to the control system of the machine tool via a separate data transmission device, which can be set in particular for the transmission of wireless data and signals from / to the monitoring module and in particular for the transmission of wired data and signals from / to the machine tool. Preferably, radio-based transmission techniques or transmission by infrared signals can be considered for the wireless transmission.

[0050] The controller may also be configured to rotate the axis at a predefined speed when a variable representative of acceleration is detected and / or to transmit this speed to the monitoring module. In the absence of concentricity errors, the central axis of the monitoring module may be substantially coaxial with the axis of rotation of the rotating axis. The machine tool / machine-turned tool may also be configured to (automatically) insert the monitoring module into the axis of the machine tool. The machine tool / machine-turned tool may also be configured to signal, e.g. via a communication device, the monitoring module to start acquiring the variable representative of acceleration. This start acquisition command may, for example, be transmitted to the monitoring module only after the machine tool has signaled to the monitoring module that it is ready to acquire data (in this case the variable representative of acceleration).

[0051] If the control system of the machine tool / machine tool determines in the monitoring module that there is no concentricity error, the machine tool / machine tool can also be set to enable workpiece machining, particularly for workpieces machined directly by the machine tool after determining that there is no concentricity error, in which case machining can begin immediately without further tool changes.

[0052] If the control system of the machine tool / machine group determines that a concentricity error exists, the machine tool / machine group can also be configured to block pending workpiece machining operations, stop the axes, put the entire machine tool into a safe state, and / or output an optical and / or acoustic error signal, for example via the machine tool / machine group's display and / or speaker. Before taking such measures, the machine tool / machine group can be configured to remove the monitoring module and / or tool from the axis and replace it. In the meantime, the axis (taper interface) can be blown out and cleaned with compressed air. Then, countermeasures are taken only if the concentricity anomaly persists after replacement of the monitoring module.

[0053] A fifth aspect relates to a concentricity monitoring signalling interface comprising a communication device configured to receive signals from the runout monitoring module of the first aspect, the runout monitoring tool holder module of the second aspect and / or the runout monitoring tool module of the third aspect and to transmit signals to the machine tool / machine tool combination of the fourth aspect. The concentricity monitoring signal transmission interface comprises a computing device connected to said communication device of the concentricity monitoring signal transmission interface and arranged to receive values ​​representative of the acceleration detected by the sensor unit of the run-out monitoring module of the first aspect, the sensor unit of the run-out monitoring tool holder module of the second aspect and / or the sensor unit of the run-out monitoring tool module of the third aspect, to determine an overall acceleration based on the recorded values ​​representative of the acceleration, to compare, during detection of the quantity representative of the acceleration, the total acceleration with a threshold value depending on the rotation speed of the axis, the rotation speed of the run-out monitoring module, the rotation speed of the monitoring tool holder module or the rotation speed of the concentricity monitoring tool module, and to determine that a run-out error of the run-out monitoring module of the first aspect, the run-out monitoring tool holder module of the second aspect and / or the run-out monitoring tool module of the third aspect is present if the total acceleration is greater than the threshold value. The communication device of the concentricity monitoring signal transmission interface is arranged to transmit a signal to the machine tool / machine tool that a run-out error of the tool rotating during operation, the run-out monitoring module, the monitoring tool holder module and / or the concentricity monitoring tool module is present.

[0054] The concentricity monitoring signal interface, which has a computing device (data processing device) and a communication device component, can communicate with the monitoring module via a communication device or via a separate data transmission device. This data transmission device can be used, in particular, for wireless data and signal transmission between the monitoring module and the concentricity monitoring signal interface, in particular for wired data and signal transmission between the concentricity monitoring signal interface and the machine tool. Preferably, radio-based transmission techniques or transmission by infrared signals can be considered for wireless transmission.

[0055] Thus, if the monitoring module transmits the corresponding measurement variable (in this case a variable representing acceleration) to the concentricity monitoring signal interface, the concentricity monitoring signal interface can be used to perform the same calculations as the monitoring module. When these calculations are performed, the results of the calculations, such as the total acceleration and / or the measurement variable on which the calculation is based, can be transmitted to the controller of the machine tool together with a signal whether or not a concentricity error is present (OK or NOK signal). If more data is to be transmitted, this can be in the form of data words between the concentricity monitoring signal interface and the machine tool, in particular a digital bus system can be used for the transmission. For this purpose, preferably field bus systems such as Profibus, Profinet, Ethercat or Ethernet can be used.

[0056] The concentricity monitoring signal interface can also be configured to activate the monitoring module, i.e. to be set in monitoring mode (measurement mode) before the monitoring module determines the variable representative of acceleration. Furthermore, the concentricity monitoring signal interface can also be configured to determine the rotational speed during acquisition of the measured variable and to transmit it to the monitoring module and / or the machine tool / machine tool. Alternatively or additionally, the rotational speed is specified by the machine tool's control system during detection or is determined by the monitoring module and transmitted to the concentricity monitoring signal interface.

[0057] The concentricity monitoring signal interface can be set to wait for a signal from the monitoring module, in particular when the monitoring module is started, the monitoring module sends a signal that it is ready for data acquisition. After completing the data acquisition, the concentricity monitoring signal interface can be set to stop the monitoring module again, i.e. to disable concentricity monitoring. This allows to save energy between individual concentricity measurements. The monitoring module can be started and stopped by the monitoring module itself or by the machine tool / machine tool combination. The concentricity monitoring signal interface can be set to send the result of whether there is a concentricity error or not by a test signal (OK or NOK) to the machine tool controller, so that the machine tool controller can take the above-mentioned measures (machining block, error display, etc.) if necessary.

[0058] A sixth aspect relates to a method for monitoring the concentricity of a tool rotating on a machine tool or a machining center during operation, the method comprising: (i) automatically inserting a monitoring module rotating during operation or a monitoring module rotating during operation and a rotating tool into an axis of the machine tool / machine tool, the rotating monitoring module comprising a sensor unit assigned to the rotating monitoring module such that the axis of rotation of the rotating monitoring module passes through the axis of rotation of the rotating monitoring module; (ii) rotating the axis of the machine tool / machine tool at a specified speed; (iii) receiving and / or detecting a quantity representative of an acceleration of a plane oriented substantially perpendicular to the axis of rotation of the rotating monitoring module while the rotating monitoring module rotates at the predetermined speed; (iv) determining a total acceleration based on the quantity representative of the recorded acceleration; (v) comparing the total acceleration with a threshold value that depends on the rotation speed of the rotating monitoring module during detection of the quantity representative of acceleration; and (vi) determining that there is a concentricity error of the rotating monitoring module and / or the rotating tool if the total acceleration is greater than the threshold value.

[0059] A "rotation monitoring module" is to be understood in particular as a concentricity monitoring tool module according to the third aspect which has an already integrated tool, whereas a "monitoring module rotating during operation and a tool rotating during operation" refers in particular to a concentricity monitoring module according to the first aspect and a concentricity monitoring tool holder module according to the second aspect, in which a tool rotating during operation is inserted before machining of a workpiece.

[0060] The concentricity monitoring process or its individual steps can be performed or at least initiated by different components such as the monitoring module (always responsible for recording the variables representative of the acceleration by the sensor unit), the machine tool / machine tool and / or the concentricity monitoring signal interface. In one variant, it is therefore envisaged that all steps of the concentricity monitoring process are performed by the machine tool. Step (iii) in particular comprises receiving the variables representative of the acceleration from the monitoring module and / or from the concentricity monitoring signal interface.

[0061] In certain variants, only steps (i) and (ii) of the concentricity monitoring process may be performed by the machine tool. Steps (iii) to (vi) may be performed by a monitoring module or by a concentricity monitoring signal interface, in the latter case step (iii) in particular comprises receiving a variable representative of the acceleration by a concentricity monitoring signal interface. This may then be followed by another step, such as sending a signal whether or not a concentricity error is present to the concentricity monitoring signal interface (if steps (iii) to (vi) are performed by a monitoring module) or to the machine tool (if steps (iii) to (vi) are performed by a concentricity monitoring signal interface).

[0062] When steps (iii) to (vi) are performed by a monitoring module, the recorded variables representative of acceleration may be temporarily stored in a data processing unit of the module or in a memory of another module, before being further processed to determine the total acceleration, preferably taking into account an initial variable representative of acceleration determined during the calibration run. The total acceleration is compared to a threshold value to determine whether it exceeds or at least reaches a specified tolerance threshold.

[0063] If steps (iii) to (vi) are performed by the machine tool or by the concentricity monitoring signal interface, the variable representative of the acceleration can be transmitted to the machine tool / concentricity monitoring signal interface continuously, in particular continuously during the measurement process (acquisition of the variable representative of the acceleration). In this case, if available, the variable representative of the initial acceleration can also be transmitted to the machine tool / concentricity monitoring signal interface. Evaluation, filtering, offsetting to an initial value, calculation of the total acceleration and comparison of the total acceleration with a threshold value can then be performed by a computing device of the concentricity monitoring signal interface / by the control system of the machine tool.

[0064] The threshold value characterizes the tolerance of the eccentricity of the tool rotating during operation and can in all the above cases be known (by one of the other components) to the computing device of the monitoring module, to the control device of the machine tool and / or to the computing device of the concentricity monitoring signal interface. The threshold value can be used as an analog or digital value, for example in micrometers (μm). The threshold value can be adjustable. This can be done, for example, directly in the monitoring module using suitable means. For example, the threshold value can be entered in the monitoring module using a magnetic pen and an ET / MODE. Alternatively, the threshold value can be entered in the control system of the machine tool / machine tool and then transmitted to the monitoring module via the concentricity monitoring signal interface as required. This procedure particularly envisages the case where steps (iii) to (vi) of the concentricity monitoring procedure are carried out by the monitoring module.

[0065] On the other hand, if the variable representing the acceleration is evaluated at the machine tool / concentricity monitoring signal interface, the threshold value can preferably be input directly to the machine tool, and if evaluated at the concentricity monitoring signal interface, the threshold value is transmitted to the machine tool and stored in memory.

[0066] The concentricity monitoring method may comprise the further optional step of activating the monitoring module so that it is set in a monitoring mode (measurement mode) before the monitoring module determines the variable representative of acceleration. This further step therefore precedes in time at least step (iii). The activation step may be followed by a step of waiting for a speed at which a value representative of acceleration (i.e. the test speed) is recorded.

[0067] The concentricity monitoring process can, if desired, have a further optional step of waiting for a signal from the monitoring module after it has been started, so that the monitoring module sends a signal that it is ready to acquire data. In a further optional step of the concentricity monitoring process, the monitoring module can be stopped again, i.e. set to a state where no concentricity monitoring is performed. This optional step is carried out once the recording of the variations according to step (iii) is completed.

[0068] In a further optional process step of the concentricity monitoring process, the rotational speed can be determined, for example, by a monitoring module, when the measured variables are recorded and transmitted to the concentricity monitoring signal interface and / or the machine tool / machine tool. If process steps (iii) to (vi) are performed by a monitoring module, this step can in particular be omitted. Alternatively or additionally, the rotational speed can be specified by the control system of the machine tool during detection.

[0069] The concentricity monitoring procedure can be carried out for a single predefined number of revolutions when recording the variable representing the acceleration. Alternatively or additionally, it is also possible to repeat the method steps (iii) to (vi) at different rotational speeds. In particular, one to five repetitions at different rotational speeds are possible, but the disclosure is not limited to a specific number of repetitions. In this case, a different rotational speed is respectively set in step (ii). The transmission of any signal regarding the presence or absence of a concentricity error to the machine tool / concentricity monitoring signal interface can, for example, be performed only once for all (test) revolutions or individually for each test revolution, whereby the corresponding test revolution can be additionally transmitted in each case.

[0070] In particular, when the method steps (iii) to (vi) are repeatedly performed, it is conceivable that the test speed is determined by the monitoring module or that the test speed is determined based on at least a measurement variable (such as another variable representing acceleration) recorded by the monitoring module.

[0071] Common to all the above mentioned aspects is that the quantities representative of acceleration (i.e. the radial acceleration in the xy plane of the monitoring module and the sensor units associated with the monitoring module) may be filtered, for example using a low pass or band pass filter, before determining the overall acceleration. Furthermore, all the above mentioned computing and control devices may be allocated suitable memories in which the received and transmitted signals described within the scope of the present disclosure and related in any way to the concentricity monitoring may be (temporarily) stored.

[0072] A seventh aspect relates to a computer program product comprising instructions for the machine tool / machine tool complex of the fourth aspect to perform the processing steps (i) to (vi) of the sixth aspect, for the runout monitoring module of the first aspect, the runout monitoring tool holder module of the second aspect or the runout monitoring tool module of the third aspect to perform the method steps (iii) to (vi) of the sixth aspect, and for the runout monitoring signal transmission interface of the fifth aspect to perform the method steps (iii) to (vi) of the sixth aspect.

[0073] The computer program product may further comprise instructions to cause any of the steps described in relation to the concentricity monitoring process to be performed by the corresponding components (monitoring module, machine tool and / or concentricity monitoring signal interface).

[0074] In principle, it is crucial for the accuracy of the runout error determination that the monitoring module / machine tool / runout measurement interface knows exactly the test speed when recording the (initial) variable representing the acceleration, in order to be able to determine accurately whether the runout of the rotating tool during operation is below a specified threshold value or not.

[0075] The machine tool controller can communicate the exact test speed to the computing device of the concentricity monitoring signal interface / monitoring module, which is considered as specified and no further checks on speed calibration are required.

[0076] In certain variants, the monitoring module may further comprise a further sensor unit arranged to detect another variable representative of acceleration in a plane radially spaced from the axis of rotation and oriented substantially perpendicularly to the axis of rotation substantially simultaneously with the detection of the variable representative of the speed. The computing device is further configured to receive another quantity representative of acceleration detected by the further sensor unit and to determine from the further quantity representative of acceleration a number of rotations of the concentricity monitoring module / concentricity monitoring tool recording module / concentricity monitoring tool module during detection of the quantity representative of acceleration. Alternatively, in some variants, the communication device may be arranged to transmit the further variable representative of acceleration to the machine tool / machine tool according to the fourth aspect and / or to the runout monitoring signal interface according to the fifth aspect.

[0077] The other (second) sensor unit can be designed similarly or identically to the (first) sensor unit in terms of its sensitivity and possible detection directions. For example, the other sensor unit can be a two-axis acceleration sensor, which is set and arranged in the monitoring module so that it can detect another variable representative of acceleration lying in the xy plane and perpendicular to the axis of rotation of the monitoring module. Alternatively, it is also possible in particular for the other (second) sensor unit to comprise a one-axis acceleration sensor, the sensing axis of which is arranged radially, i.e. so that this one-axis acceleration sensor can detect another variable representative of acceleration lying in the xy plane and perpendicular to the axis of rotation of the monitoring module. In case of using a one-axis acceleration sensor for the additional sensor unit, the "other variable representative of acceleration" usually includes only a single "variable representative of acceleration". To this end, unless otherwise specified in the relevant place or unless a contrary technical meaning is evident,

number

[0078] In one variant, the additional sensor unit may also comprise two opposing acceleration sensors arranged in a plane radially spaced from the axis of rotation and perpendicular to the axis of rotation. In this case, the acceleration sensors each have a measurement axis which is in line or in a plane perpendicular to the plane containing the axis of rotation. Preferably, the acceleration sensors provide measurements in which the average value of each of the other variables representing acceleration is formed. As mentioned above, the speed determined by only one sensor may be influenced by a possible concentricity error, but by arranging two opposing sensors, this influence can be minimized or eliminated. In the presence of a runout error, for example, the radial distance to the axis of rotation of the first acceleration sensor increases and the radial distance of the second acceleration sensor decreases accordingly. The average value of the acceleration measured by the two opposing acceleration sensors is therefore independent of any possible concentricity error. The calculation of the rotation speed can be carried out in a computing device, if necessary.

[0079] If other variables representing acceleration are sent to the machine tool / concentricity monitoring signal interface, the velocity may be determined based on these variables by a computing device in the machine tool controller / concentricity monitoring signal interface.

[0080] The further sensor unit may, for example, be arranged adjacent to and / or in contact with an inner circumferential surface of the monitoring module, which may be essentially cylindrical. The further sensor unit may therefore, in particular, be arranged outside a (off-center) central location, so that it is radially spaced from the sensor unit and the rotation axis of the monitoring module does not pass through the further sensor unit.

[0081] The eccentric acceleration sensor arranged in this way (as a separate sensor unit) supplies other variables (as acceleration values ​​or transducer values) representative of the acceleration, from which the velocity is then calculated, which variables represent the centrifugal acceleration of the separate sensor unit.

[0082] In some variations, when the rotation axis of the monitoring module is oriented substantially horizontally during detection of the variable representing acceleration, the computing device of the monitoring module may be configured to determine the rotation speed of the monitoring module during detection of the variable representing acceleration based on the signal frequency prevailing during detection of the variable representing acceleration.

[0083] This is particularly advantageous for applications or at least concentricity tests in which the monitoring module must be oriented exclusively horizontally, since it means that no additional sensor units are needed in the monitoring module to determine the speed. This allows, among other things, to save costs. The reason for this is that when recording the variables representing the acceleration, if the monitoring module is oriented horizontally, a sinusoidal signal caused by the acceleration due to gravity is superimposed on these variables. This sinusoidal signal can be analyzed separately in the computing device of the monitoring module, which sinusoidal signal provides an amplitude that at least approximately corresponds to the acceleration due to gravity (1g). The frequency of the sinusoidal signal corresponds to the rotation speed being detected, i.e. the test rotation speed. This type of speed determination is particularly efficient since no calibration is required.

[0084] In some variations, the monitoring module may further comprise a photosensitive unit having a photosensitive surface located on the outer periphery of the monitoring module, the photosensitive unit being adapted to detect brightness differences during detection of the quantity representative of acceleration, and the computing device being adapted to determine a rotational speed of the monitoring module based on the frequency of the brightness differences during detection of the quantity representative of acceleration.

[0085] This can therefore be an optical test speed detection, whereby the light-sensitive unit can for example comprise a light detector, for example a photodiode, which can be integrated in the monitoring module with its light-sensitive surface facing radially outwards. During speed detection, a light signal that is generated during the rotation of the monitoring module due to the ambient light conditions can be detected. A series of light and dark differences creates a light pattern, which is converted into a voltage by the light-sensitive unit. This light pattern, and therefore also the voltage pattern, is repeated with every rotation. The fundamental frequency of the light pattern can therefore be determined by applying a corresponding signal evaluation. The fundamental frequency of this light pattern corresponds to the test speed.

[0086] In a particular variant, it is conceivable to use an IR photodiode in the light-sensitive unit. In this case, it is not the ambient light that is detected, but light rays with frequencies in the infrared range, emitted, for example, by IR LEDs assigned to the machine tool and arranged on the machine tool in order to illuminate the light-sensitive surface of the machine tool when the monitoring module is arranged on the axis of the machine tool. In this way, the test speed can be reliably determined, especially under weak (dark) lighting conditions. This type of optical test speed detection is particularly efficient since it does not need to be calibrated.

[0087] In some variants of the monitoring module, at least the sensor unit, preferably an additional further sensor unit, can be arranged on a sensor circuit board, the sensor circuit board being connected to a circuit board holder, the position of which can be adjusted perpendicular to the axis of rotation via an adjustment means of the monitoring module.

[0088] In one variant, the sensor circuit board is fixed to the circuit board holder. Moreover, in one variant, the circuit board holder is suspended (mounted) and in one variant is precisely located in the (rotational) center of the monitoring module via adjustment means. For example, a threaded pin radially mounted on the circuit board holder of the monitoring module is used for lateral fine adjustment of the circuit board holder and thus of the sensor unit. In one variant, this fine adjustment is in particular performed by the manufacturer, although the disclosure is not limited thereto.

[0089] Other grub screws, which are different from the grub screws for the fine adjustment of the blank holder and which can be used in particular for the fine adjustment of the monitoring module by the user, can have a different weight and / or can be designed to accommodate additional mass. The fine adjustment of the monitoring module can be performed via threaded holes on the periphery of the monitoring module using these threaded pins, in particular after a tool change.

[0090] In certain variants, the monitoring module may further comprise a power supply unit preferably adapted to switch from a power saving or standby mode to the monitoring mode in response to a wake-up signal and / or to switch the sensor unit, the further sensor unit, the computing device and / or the communication device from a power saving or standby mode to the monitoring mode in response to a wake-up signal.

[0091] For example, activation of the concentricity monitoring module described above may include activation by a wake-up signal.

[0092] In the energy saving mode, the computing unit (data processing unit), the sensor unit and the communication unit (data transmission unit) of the electronic unit of the monitoring module can be put into standby and consume relatively little energy. In the monitoring mode (which is also the measurement mode), the electronic unit can be put into a standard mode in which it can perform all the measurements described in the context of this disclosure. In the measurement mode, the electronic unit consumes more energy than in the energy saving mode.

[0093] In some variants, the energy supply unit can comprise an energy storage unit for storing electrical energy. In some variants, the energy supply unit can also comprise a generation unit for generating electrical energy. The energy supply unit can thus be responsible for generating and / or storing, and preferably also for regulating the supply voltage of all components of the electronic unit. The energy supply unit can supply the components of the electronic unit with energy stored in at least one battery or at least one accumulator. In this case, the generation unit can be omitted, the battery / accumulator can have a relatively large capacity and / or a relatively high energy density. Alternatively or additionally, the monitoring module can generate its own power via the generation unit, for example using the energy of the rotating shaft of the machine tool or a pressurized medium. These various forms of energy can be converted into electrical energy by using the generation unit. In these cases, relatively small energy storage devices with low capacity and / or low energy density (especially compared to the energy supply from the accumulator), such as one or more small batteries and / or one or more small capacitors, can be used for energy storage. The generation unit can have a first part, for example with three induction coils arranged offset from each other by 120°. The second part of the generating unit, which is rotatable relative to the first part of the generating unit, can comprise, for example, one or more permanent magnets. Alternatively, the first part can comprise a permanent magnet and the second part can comprise a coil. When the first part rotates relative to the second part, alternating voltages are generated that are shifted by 120° relative to each other in terms of phase position. However, the disclosure is not limited to this particular embodiment of the generating unit. For example, variants with six induction coils, two of which are connected in series, or nine induction coils, three of which are connected in series, are also conceivable. In these cases, there are more permanent magnets in the second part of the generating unit, and in particular the number of permanent magnets increases as the number of induction coils increases.The power supply unit may also include a rectifier that converts the AC voltage generated by the power generation unit into a DC voltage and smoothes it.

[0094] In a particular variant of the monitoring module, the wake-up signal is or is triggered by a signal generated by another sensor unit as soon as another variable representing acceleration exceeds a wake-up threshold or received via a communication device from the machine tool / machine tool complex of the fourth aspect and / or the monitoring signal transmission interface of the fifth aspect or generated when the amount of energy generated by the energy supply unit exceeds a predetermined level.

[0095] In a variant, the additional sensor unit can be set to generate a wake-up signal when a set wake-up threshold is reached or exceeded, which enables the power supply unit, the computing unit and the communication unit of the monitoring module to switch from the energy saving mode to the monitoring mode. In order to ensure the safest possible start-up of the monitoring module or its components and to avoid false start-up, the following sequence (start-up sequence) is conceivable:

[0096] First, the monitoring module is inserted into the spindle of the machine tool (see, for example, step (i) according to the sixth aspect). Then, the monitoring module is rotated on the shaft (see step (ii) according to the sixth aspect), which causes the separate sensor unit to undergo centrifugal acceleration and generate a wake-up signal. The wake-up signal of the separate sensor unit wakes up the electronic unit of the monitoring module. As mentioned above, the electronic unit can check whether there is actually a rotation speed in the monitoring module. If the monitoring module is actually rotating, the electronic unit remains in the monitoring mode. In one variant, the monitoring module (in the shaft or alone, i.e. removed from the shaft) does not rotate. The electronic unit can check whether there is still a speed in the monitoring module. If the monitoring module is not actually rotating, the electronic unit returns to the energy saving mode. This allows the monitoring module to remain in the monitoring mode as long as necessary, but for as short a time as possible. This ultimately saves energy for powering the components of the electronic unit or the entire monitoring module.

[0097] When receiving a wake-up signal from the machine tool / rotation monitoring signal interface, the control device of the arithmetic device of the machine tool / rotation monitoring signal interface sends an activation signal (wake-up signal) to the monitoring module via the corresponding communication device which switches to monitoring mode. If the wake-up signal is generated when the amount of energy generated by the energy supply unit exceeds a predefined level, the monitoring module is also first changed to the axis of the machine tool according to step (i) according to the sixth aspect. As soon as the monitoring module rotates according to step (ii) according to the sixth aspect, the power generation unit starts to generate energy. When a certain level is reached, the electronic unit is automatically energized and set to monitoring mode. All variants of activation, i.e. in addition to setting the monitoring module to monitoring mode, impact events such as a fall to the floor or a collision with an object in the machine room, can be recorded. The results of this recording can be stored in the module or can be sent to the machine tool and / or the concentricity monitoring signal interface. The above-mentioned activation sequence may or may not be performed regardless of which variant is used to activate the monitoring module. In some variants, the generating unit comprises a stator that is directly or indirectly coupled to the tool holder of the monitoring module or that can be directly or indirectly coupled to the tool holder according to the first aspect, the generating unit further comprising a rotor associated with the monitoring module to cooperate with the stator such that the generating unit generates electric energy upon rotational acceleration of the monitoring module about the rotation axis. The rotational acceleration is a positive or negative rotational acceleration that is generated when the shaft speed increases or when the shaft speed decreases. Alternatively, the stator can be directly or indirectly coupled to the monitoring module. The stator can be a first part of the above-mentioned generating unit. In this case, the rotor can be a second part of the above-mentioned generating unit. Alternatively, the stator can be a second part of the above-mentioned generating unit. In this case, the rotor can be a first of the above-mentioned generating units. In this case, a flywheel with permanent magnets can represent the rotor. The stator can be provided with one or more induction coils.The induction coil can be, for example, a coil with a manganese-zinc-ferrite core interconnected via a circuit board. Furthermore, the coil can be placed in a corresponding recess in the coil cage and / or glued to the coil cage. This ensures a high level of stability even at high machining speeds. When the shaft of the machine tool is accelerated around the axis of rotation (or later decelerated again), due to the inertia of the flywheel, a speed difference occurs between the stator and the rotor (i.e. the flywheel). This induces a voltage in the induction coil, which is either directly supplied to the load (i.e. the components of the electronic module itself, in particular if it is currently in monitoring mode) or stored in the energy store of the monitoring module. In this way, when the shaft speed changes, a voltage is generated until the flywheel reaches the (new) shaft speed, i.e. until there is no more negative or positive acceleration. The theoretically obtainable mechanical energy (rotational energy) when the shaft speed changes is calculated as follows:

number

number

[0098] The time required for a concentricity monitoring cycle, i.e. the start-up of the electronic unit, the recording of a variable representative of the acceleration, the other variable representative of the acceleration and, if applicable, the rotation speed(s), the determination of the overall acceleration, the determination of whether a concentricity error is present and the transmission of a signal whether a concentricity error is present or not, can in particular be between 1 and 2 seconds. To cover the energy requirements of this period, the amount of energy that can be generated by the generator unit when the shaft and thus the rotating tool reach the normal machining speed of the workpiece is already sufficient. However, if the amount of energy is not sufficient in a given case, for example because the machining speed is very low, additional energy can be generated by repeatedly changing the speed. For example, the shaft can be accelerated to 1000 rpm for a relatively short time (for example 2-3 seconds) and then decelerated to a machining speed of 500 rpm, thereby generating energy during acceleration and deceleration. In some variants, the monitoring module can also be equipped with a fluid channel extending in a liquid-tight manner between two outsides of the monitoring module spaced apart in the axial direction of the rotating shaft. In some variants, the power generating unit may comprise a turbine unit with a turbine wheel arranged in the fluid channel and a generator integrated in the turbine unit arranged to generate electrical energy when the fluid flows through the turbine wheel. In this way, the energy conversion of the pressurized medium described above is performed. The coolant and / or lubricant used in the machine tool may be realized. The medium available at the axis may be sent to the turbine via a fluid channel and / or a coolant pipe in the monitoring module.

[0099] The flow of the medium through the turbine wheel causes it to rotate and induces a voltage by means of an integrated generator, which voltage is supplied as a load to the monitoring module itself or to its components or is stored in an energy storage unit of the monitoring module. In particular, the turbine wheel can be the second part of the above-mentioned power generating unit (generator). In particular, a permanent magnet can be attached to the underside of the turbine wheel or can be integrated into the turbine wheel. A stator with an induction coil can be permanently arranged on a circuit board in the monitoring module below the turbine wheel. To monitor the function of this type of energy generation, the monitoring module can, for example, output an error to the machine tool / concentricity monitoring signal interface if the monitoring module detects that no energy is being generated, even if the spindle of the machine tool is accelerated positively or negatively.

[0100] Since the sensor unit can be located exactly in the center (of the axis of rotation) of the monitoring module, it may be necessary to direct the medium, which is usually supplied centrally via the coolant channel, through the sensor board. For this purpose, the monitoring module can be provided with a distributor that can direct the flow of medium towards the sensor board and the sensor unit while simultaneously supplying the medium to the rotating tool.

[0101] The monitoring module can be continuously powered by generating its own power (self-powering). This can be particularly desirable if data is continuously recorded by the sensor unit or the additional sensor unit during the machining process of the workpiece and transmitted to an external evaluation unit, such as a concentricity monitoring signal interface or a machine tool. In some variants of the monitoring module, the sensor unit is configured to record initial values ​​representative of the acceleration of a surface oriented essentially perpendicular to the axis of rotation at an essentially constant rotation speed or at several different essentially constant rotation speeds, apart from the normal operation of the monitoring module, in particular rotating with the axis, whereby the computing device is configured to record initial values ​​representative of the acceleration of a surface oriented essentially perpendicular to the axis of rotation at an essentially constant rotation speed or at several different essentially constant rotation speeds and to store the initial quantity representative of the acceleration together with the corresponding rotation speed(s) in the memory of the monitoring module and / or the communication device transmits the initial quantity representative of the acceleration, preferably together with the corresponding rotation speed(s) to the machine tool / machine tool according to the fourth aspect and / or to the concentricity monitoring signal interface according to the fifth aspect. The initial values ​​representing the accelerations can be recorded apart from normal operation (operation during which the machine tool can machine a workpiece) and in particular in calibration mode (running a calibration). This calibration is carried out in particular under conditions in which the machine tool, the axes, the tool changer, the working area of ​​the machine tool, the concentricity monitoring signal interface and the monitoring module (here, in particular, an exact centering of the sensor units) are operating without errors. In particular, in calibration mode, the tool holders of the axes should be as ideally flat as possible and there should be no chips or other dirt in the area of ​​the axes and tool holders. If necessary, the manufacturer and / or the user can monitor this.

[0102] A calibration, which is possible in particular by the manufacturer, can be carried out, because the assembly to position the sensor unit exactly in the center (i.e. on the rotation axis of the monitoring module) can be very complicated (mainly due to manufacturing and assembly tolerances). Also, because of certain tolerances, it is not always possible to clamp the monitoring module exactly in the center of the axis (so that the axis is exactly coaxial with the rotation axis of the monitoring module). This can result in an "off-center position" of the sensor unit, in particular where the inertial axis of the sensor unit (e.g. an axis that does not necessarily have to be the sensing axis) (or, alternatively, the inertial axis of the acceleration sensor of the sensor unit) is radially spaced from the rotation axis of the monitoring module, in particular within the tolerance distances mentioned above, while maintaining the above-mentioned angular error between the rotation axis of the monitoring module and the inertial axis of the sensor unit. This eccentricity can result in an offset value, which distorts the actual value representing the acceleration.

[0103] For this purpose, the above-mentioned offset values ​​are determined during the calibration run as initial values ​​representative of the acceleration and are taken into account when calculating the overall acceleration. A calibration run is therefore a "learning cycle" for determining the initial values ​​of the corresponding monitoring modules representative of the acceleration. The calibration can be performed in a calibration mode, in which the initial values ​​representative of the acceleration are determined for one test speed or for several test speeds. The (one or more) test speeds themselves can be specified and / or determined as described above. In particular, if an additional sensor unit is used to determine the test speed, this speed determination can also be calibrated by the manufacturer or by a calibration process at a known speed.

[0104] A function of initial values ​​representing the acceleration dependent on the test speed can be calculated. This speed dependent function can be stored in the memory of the monitoring module and / or sent to the concentricity monitoring signal interface / machine tool. The calculations required for calibration can be performed by the machine tool / concentricity monitoring signal interface.

[0105] The detection of the initial variable representative of acceleration, like the detection of the variable representative of acceleration, takes place over a certain evaluation time and can be characterized in particular by a certain number of revolutions (for example between 4 and 100). In order to determine the initial acceleration variable as accurately as possible, the speed(s) can be essentially constant or can vary within a range of at most 10% of the speed(s) during the evaluation time. It may be intended to start recording the initial value representative of acceleration only when the speed(s) is reached, i.e. outside the start-up phase of the axis to the corresponding speed(s). This also applies to the determination of the variable representative of acceleration. If the initial quantity representative of acceleration and the quantity representative of acceleration at essentially the same speed are known, the total acceleration can be determined as a function of these quantities in the sense of the resulting total acceleration. As with the method according to the sixth aspect, the calibration can be carried out at least in part by the different components mentioned above, such as the monitoring module, the run-out monitoring signal interface and the machine tool, and / or by the interaction of these components.

[0106] If the calibration is performed entirely by the monitoring module itself, the monitoring module of the machine tool / concentricity monitoring signal interface can send a signal that the calibration is ready to be performed. The initial variables representing the acceleration can then be recorded, filtered and stored, which allows, in particular, recordings to be made at a stable speed over the recording period. If the calibration is performed for several speeds, the respective speeds can also be determined during the acquisition. The speed can then be changed if necessary, and the filtering and determination of the variables representing the initial acceleration can be performed again for the changed speeds. This results in the acquisition of a test speed and initial acceleration pair, which can be stored in the monitoring module in the case of the speed-dependent functions described above, i.e. in the case of a calibration run at a single speed. Once this sequence is completed, the monitoring module can send a signal to the machine tool / concentricity monitoring signal interface that the calibration run is complete. Alternatively or additionally, the monitoring module can send a signal (OK or NOK) to the machine tool / concentricity monitoring signal interface to signal that the calibration process has been successfully completed or that an error has occurred.

[0107] Alternatively, the initial values ​​representing the accelerations can be filtered and stored in the machine tool / concentricity monitoring signal interface. Here too, the tool module can, if necessary, transmit to the machine tool / concentricity monitoring signal interface a readiness to perform a calibration in response to a request from the machine tool / concentricity monitoring signal interface. The initial values ​​representing the accelerations can be recorded at a stable speed during a recording period. The recorded values ​​can be continuously transmitted to the machine tool / concentricity monitoring signal interface, for example, until the recording period is reached. The speed can then be changed if a calibration is performed at multiple speeds. The initial values ​​representing the accelerations can then be recorded and transmitted at the newly set speeds until the recording time is reached again. Once the initial acceleration values ​​for all test speeds have been recorded and transmitted, the calibration run can be terminated, for example, by a signal from the machine tool / concentricity monitoring signal interface. The initial acceleration values ​​are then filtered in the machine tool / concentricity monitoring signal interface and stored together with the speed(s) during the calibration run, in particular as a speed-dependent function of the initial acceleration values.

[0108] In some variants of the monitoring module, the computing device is further arranged to process the quantity representative of the acceleration detected by the sensor unit and / or the quantity representative of the initial acceleration and / or the quantity representative of the acceleration in a specific time window between 50 ms and 200 ms in the form of a data packet, the processing being performed by operations such as signal filtering, averaging and / or determining a frequency spectrum for each time window, and to transmit the processed data packet to the machine tool / machine tool of the fourth aspect and / or to the concentricity monitoring signal interface of the fifth aspect.

[0109] This is a variant of a continuous process data transmission in which all variables recorded by the sensor units and / or other units (e.g. photosensitive units) of the monitoring module are continuously transmitted to the machine tool / concentricity monitoring signal interface. This is particularly important when monitoring and controlling complex manufacturing processes in which the monitoring module / machine tool / concentricity monitoring signal interface is integrated. This continuous transmission may require a high bandwidth, especially if a high time resolution is required (e.g. when also performing vibration measurements based on the variables recorded by the sensor units) or if a large number of recorded variables are transmitted simultaneously by the monitoring module. Wireless data transmission between the monitoring module and the machine tool / concentricity monitoring signal interface may result in a bottleneck and may have a limiting effect on the data transmission. In these cases, the variables recorded by the sensor units can be partially analyzed in the monitoring module, so that a secure and completely wireless data transmission can take place. In this variant, it is particularly conceivable for the monitoring module to monitor the concentricity of a rotating tool continuously during operation, preferably during a machining cycle of a workpiece (or at least a part of a machining cycle executed using the corresponding monitoring module). For this purpose, the machine tool / concentricity monitoring signal interface may wait, possibly on request, for a signal from the monitoring module which sends a signal that it is ready for data acquisition. In particular, the monitoring module may continuously record variables representative of acceleration and other variables representative of acceleration as process parameters and may transmit data packets containing these and possibly other process parameters such as coolant flow and / or pressure or determined vibrations to the machine tool / concentricity monitoring signal interface within a time window or at the end of the time window. The recorded process parameters and / or the data packets may be temporarily stored in a memory of the monitoring module.

[0110] As part of preparing the process parameters as data packets, which is not necessary but is particularly useful for complex process parameters such as vibration, for example the RMS value of the recorded variables can be determined over a time window. The data packets can also include peak values ​​occurring within the time window and the frequency spectrum of the recorded variables for each time window determined using an FFT. In this way a data packet summarizing the process variables determined in each time window can be sent to the machine tool / concentricity monitoring signal interface for each time unit.

[0111] In these cases, the evaluation of the data packets with the speed determination, the filtering of the process parameters or the recorded acceleration variables, the determination of the acceleration values, the determination of the total acceleration and / or the comparison of these with threshold values ​​can take place in the machine tool / concentricity monitoring signal interface. If the evaluation takes place in the concentricity monitoring signal interface, the concentricity monitoring signal interface can send a signal to the machine tool that the monitoring module has or does not have a concentricity error.

[0112] In some variants of the monitoring module, the communication device is further arranged to transmit, when the buffer of the monitoring module is at least approximately full, a quantity representing the acceleration detected by the sensor unit and / or a quantity representing the initial acceleration and / or a quantity representing another acceleration detected by another sensor unit and / or the rotational speed and / or a data packet of the monitoring module during detection of the quantity representing the acceleration to the machine tool / machine tool according to the fourth aspect and / or to the concentricity monitoring signal interface according to the fifth aspect.

[0113] This variant can, for example, in particular be combined with the variant of transmitting the recorded process variables to the machine tool / concentricity monitoring signal interface for each time window (in this respect the explanations given for this variant apply analogously). It is conceivable that the recorded process variables are first temporarily stored in the monitoring module and that the transmission of the process variables starts as soon as the memory of the monitoring module is full or 90%, 80% or 70% full. This transmission can be maintained until the intended recording period is reached or until the memory of the monitoring module is nearly empty again (for example only 30%, 20% or 10% full) or completely empty.

[0114] In some variations of the monitoring module, the computing device may be arranged to determine the total acceleration based on subtracting a quantity representative of the initial acceleration from a corresponding quantity representative of the acceleration.

[0115] Such a determination of the overall acceleration can of course also be made by the machine tool / concentricity monitoring signal interface, even if not all steps according to the sixth aspect are performed by the monitoring module.

[0116] Thus, the total acceleration value can be the result of the variables (ax, ay) representing the acceleration from the sensor unit, taking into account the initial variables (initial values ​​ax_initial, ay_initial) representing the acceleration. If these variables are known essentially at the corresponding velocities, the total acceleration (in the sense of the resulting total acceleration) can be calculated as:

number

[0117] The threshold to which this total acceleration is compared to determine whether there is a concentricity error of the monitoring module can in particular be a threshold related to a deviation from an initial value of the variable representing the acceleration. This threshold can therefore characterise the range of still tolerable eccentricity of the rotating tool (i.e. a deviation from ideal concentricity, but still no concentricity error in the sense of the present disclosure). Thus, if the total acceleration exceeds the threshold, in particular a concentricity error of the monitoring module may be present (a NOK signal is sent to the machine tool / concentricity monitoring interface). The (speed-dependent) threshold can for example be specified as a digital or analogue value, for example as a μm value.

[0118] In some variants of the monitoring module, the computing device may be arranged to determine the amount of run-out error and / or the direction of the run-out error when a run-out error is present. The communication device may be arranged to transmit the amount and / or the direction of the run-out error to the machine tool / machine tool according to the fourth aspect or to the run-out monitoring signal interface according to the fifth aspect. Additionally or alternatively, the communication device may be configured to transmit a signal of the run-out error to the machine tool / machine tool according to the fourth aspect and / or to the run-out monitoring signal interface according to the fifth aspect when a run-out error is present, particularly while the monitoring module is rotating with the axis.

[0119] In this way, preferably before machining the workpiece with the machine tool, a signal can be sent quickly and efficiently to the machine tool / concentricity monitoring signal interface that a concentricity error is present, in particular to the monitoring module, so that the tool can take appropriate measures quickly. The amount of the concentricity error and the direction of the concentricity error can be sent, for example, as a digital value (e.g. 30 μm at 110°). The amount of the concentricity error r is calculated taking into account a_resulting and the speed n at the time of detection as follows:

number

[0120] In some variants, the monitoring module is configured to detect another variable representative of acceleration, determine the total acceleration, determine whether a concentricity error is present and transmit a signal whether a concentricity error is present, during a period during which the monitoring module is moved, in particular with the axis, from the axis start position to the machining position of the workpiece, in particular less than 5 seconds, preferably less than 3 seconds. The period can be, for example, between 1 and 2 seconds. Thus, in contrast to many other tactile concentricity monitoring methods (or methods using laser measurement systems), the entire concentricity check, including the transmission of the results, can be performed essentially in parallel with the machining time, i.e. during the approach of the rotating tool to the machining position. In some variants, the monitoring module can further comprise at least one antenna unit having at least one antenna and at least one antenna cover, the antenna being arranged inside the monitoring module and the antenna cover covering the antenna from the axis to the outside. The antenna cover extends in the axial direction of the rotating axis over a length greater than the antenna.

[0121] In particular, the antenna can be used for wireless data transmission and communication with the machine tool / concentricity monitoring signal interface. One separate antenna or two (or three or more, if necessary) separate antennas may be present in the antenna unit. Alternatively, two, three or more antenna units may be provided, each with an antenna and an antenna cover. In some variants, the antenna cover may be omitted. As a result, particularly when using high-speed rotation monitoring modules, better circular radiation characteristics may be achieved and better data transmission quality may be achieved.

[0122] Common to all the above-mentioned aspects is the possibility of detecting vibrations occurring in particular while the machine tool is processing a workpiece with a monitoring module. For this purpose, in particular the variables representative of acceleration recorded by the sensor unit and / or other variables representative of acceleration recorded by additional sensor units can be analyzed. In particular the oscillation amplitudes (peak-to-peak values), the root mean square (RMS) values ​​and the RMS values ​​of the harmonic vibration components of the recorded variables can be analyzed. Advantageously, the frequency spectrum of the recorded variables can also be analyzed, for example using FFT.

[0123] If the sensor unit / additional sensor unit comprises a 3-axis acceleration sensor, the acceleration variables can be analysed in all three axial directions (X,Y,Z). The same applies to a 2-axis acceleration sensor, where the acceleration variables can be analysed in both axial directions (X and Y). Alternatively, it is also conceivable to analyse the vibrations based on the acceleration occurring along one of the three or two axial directions. In these cases, in particular the axial direction in which the greatest acceleration occurs can be analysed.

[0124] The vibrations (oscillations) can be analyzed in a monitoring module. If the vibrations reach or exceed a defined tolerance threshold, the monitoring module sends an error signal to the machine tool / concentricity monitoring signal interface. Alternatively, only the raw data on which the vibration analysis is based, i.e. the variables representing the accelerations and / or other variables representing the accelerations, can be sent to the machine tool / concentricity monitoring signal interface, which are analyzed and compared to the defined tolerance thresholds. If a tolerance threshold is exceeded, the machine tool can change the machining parameters and / or stop machining and set the machine tool in a safe state. By measuring and analyzing the vibrations and other process parameters during the machining of the workpiece, in addition to the monitoring of the concentricity, a monitoring of the entire machining process, the state of the tools (wear, tool breakage) and the state of the axis bearings can be performed, in particular in order to be able to react quickly in case of problems.

[0125] Thus, in some variations, the computing device of the monitoring module sets at least one process parameter when the monitoring module rotates, in particular with a rotating tool and / or tool holder and / or shaft, the at least one process parameter including vibration, temperature, coolant pressure, coolant flow rate, cutting force and / or torque, and if one of the parameters exceeds or falls below a certain threshold, the monitoring module / machine tool of the concentricity monitoring signal interface sends a corresponding error signal.

[0126] For this purpose, each of the monitoring modules can have additional sensors, for example a temperature sensor for monitoring the temperature of the tool during the machining of the workpiece by the machine tool, in particular equipped with the monitoring module. Furthermore, strain gauge sensors and / or piezo sensors can be provided on / in the monitoring module in order to determine variables such as forces (e.g. cutting forces) and torques occurring during the machining of the workpiece. A flow sensor can also be assigned to the monitoring module, which can make it possible to continuously check, for example, whether sufficient medium is flowing through the turbine wheel to generate energy by the turbine unit.

[0127] The flow sensor may comprise a flow sensor unit arranged in the monitoring module. Alternatively, the medium flow rate may be determined by the speed of the turbine wheel. Additionally and / or alternatively, the monitoring module may be provided with a pressure sensor measuring the pressure of the medium in the fluid channel / coolant pipe. In case of a pressure drop, it may be inferred that there is a lack of medium flow and, as a result, a problem with the energy production by the turbine unit. The concentricity monitoring signal interface and the machine tool may be configured to receive the error signal sent from the monitoring module (via the concentricity monitoring signal interface in the case of the machine tool) and to initiate appropriate measures.

[0128] In another variant, to further save energy, the monitoring module can be kept in a "deep sleep" state completely until "wake-up". In this case, operational readiness can be established at a predefined rate (sequence) for a predefined period (sequence) (in each case) and by manual activation using an input device. This is in contrast to established wireless transmission systems, where the end device wakes up from deep sleep at regular intervals and asks if communication is required or periodically transmits a status. In the variant presented here, the monitoring module can only transmit event signals for specific events. The receiver unit confirms the reception of the signal by a confirmation signal, as described for example in EP 2 208 017 A1. The confirmation signal can also contain instructions. These instructions can include a change in the operating mode of the wireless transmission, so that the monitoring unit does not transmit a further event signal but switches to a two-way data transmission.

[0129] In one variant, the operating mode can be selected via a speed level profile. The communication between the monitoring module and the receiving base station can be established, for example, in the variants described in EP 2208017. In one variant, the monitoring module is made known to the base station by a teach-in process or a pairing process. In one variant, the monitoring module performs a teach-in process by the axes of the machine tool executing a predefined speed pattern or a predefined first speed profile. The monitoring module can be set to recognize the profile by its own sensors (for example an acceleration sensor) or by evaluation of the generator voltage and switching the operating mode "execute teach-in process or pairing process". Further functions can be performed by the monitoring module using predefined additional speed profiles, for example the "execute calibration process" function. Here, the monitoring module automatically records the calibration values. After successful calibration, it sends a confirmation signal. In one variant, the (i) speed of the spindle of the machine tool, (ii) duration of a given speed (sequence), (iii) gradient of change from one speed level to the next and / or (iv) duration of change from one speed level are provided as parameters of a speed profile. In particular, the individual parameters of these profiles can be detected by analyzing the voltage of the generator. An example of such a speed profile is 200 rpm for 1 second, then 400 rpm for 0.5 seconds, then 200 rpm for 1 second. Another example of such a speed profile is 200 upm for 1 second, then 500 upm for 0.5 seconds (gradient of change: Δupm / Δt=300 / 0.5=600), then 500 upm for 0.5 seconds, then 300 upm for 0.5 seconds (gradient of change: Δupm / Δt=200 / 0.5=400), then 300 upm for 1 second. It should be understood that a sequence may have several different speed steps, each of which may be longer or shorter, and this also applies to the duration of the speed changes.

[0130] In addition to the functions "Perform teach-in process or pairing process" and "Perform calibration process", functions "Wake up or generate wake-up signal", "Assume monitoring mode or measurement mode", "Assume deep sleep or standby mode" and other functions are transmitted from the machine tool control system to the concentricity monitoring system by such predefined speeds or speed sequences of the machine tool axes.

[0131] In one variant, the concentricity monitoring module, the concentricity monitoring tool holder module or the concentricity monitoring tool module is set up to start detecting a variable representing the acceleration, detecting another variable representing the acceleration, determining the total acceleration, determining whether a concentricity error is present or sending a signal whether a concentricity error is present or not only when a defined rotational speed is reached, so that during the evaluation time the axis rotational speed is essentially constant or varies within a range of up to 10% of the rotational speed.

[0132] The machine tool (or its controller), the runout monitoring signal interface and the monitoring module (i.e. both the runout monitoring module according to the first aspect and the runout monitoring tool holder module according to the second aspect as well as the runout monitoring tool module according to the third aspect) may be included in a runout monitoring system. Such a runout monitoring system may comprise all the features mentioned above in relation to the individual components. In particular, the concentricity monitoring signal interface may serve as a communication interface between the monitoring module and the machine tool (machine interface). At least a partial evaluation of the variables recorded by the monitoring module may be performed at the machine interface (concentricity monitoring signal interface) or only data transmitted from the monitoring module to the machine tool for performing corresponding evaluations at the machine tool itself may be transferred by the machine interface. The communication and data transmission between the monitoring module and the machine interface may be wireless, preferably radio-based or infrared transmission. The communication and data transmission between the machine interface and the machine tool may be wired or, in case of analysis at the machine interface, for example using I / O status signals. Alternatively, data words (for transmitting large amounts of data, e.g. for continuous process data monitoring) can be transmitted between the machine interface and the machine tool via a digital bus system (such as a field bus system like Profibus, Profinet or Ethercat®). The applicant has the right to file an independent claim for such a concentricity monitoring system.

[0133] The above-mentioned aspects provide a modular solution for improving the concentricity monitoring of tools rotating during operation. In particular, no additional installation costs are required if a measurement system with a radio-based communication interface is already installed on the machine tool. This results in an easier retrofit and (in addition to the general design of the monitoring module) a significant cost reduction compared to conventional axis-integrated systems, since the complex design of the axis-integrated sensors and their deep integration into the machine tool make these systems expensive and retrofitting requires significant interventions in the machine tool structure.

[0134] Modularity also allows for greater flexibility, as the monitoring module is not machine-specific and can be used with various machine tools. This means that task-specific tools with concentricity monitoring can be combined with little effort as required. When converting entire production lines, the monitoring module can be flexibly combined with other cutting tools.

[0135] Compared to tactile concentricity checks and concentricity measurements by laser measuring systems, concentricity monitoring in the manner described above can be performed even faster, in particular in parallel with the machining time during the approach of the tool to the machining point, since the concentricity monitoring module provides the required measurement results in a very short time.

[0136] It will be apparent to one skilled in the art that the above-described aspects and features (except those relating to the structural components described only with respect to the monitoring module) may be combined as desired in a monitoring module, a runout monitoring signal interface, a machine tool, a runout monitoring system and / or a method for monitoring the runout of a tool rotating within a machine tool / machine machining center during operation. [Brief description of the drawings]

[0137] Further objects, features, advantages, possible applications and possible modifications are shown in the following description of non-limiting examples of embodiments and variants with reference to the associated drawings. All features described and / or shown in the figures show the objects disclosed herein individually or in any combination. The dimensions and proportions of components shown diagrammatically in the figures are not to scale. Identical or similarly functioning components are provided with the same reference numerals. Whenever a range of values ​​is mentioned in this disclosure, the upper and lower limits of the range are included in the range. It should be noted that all calculations in this disclosure and the representation of values ​​in figures 1-3 are performed on digital output values ​​(raw data) from, for example, an acceleration sensor. Alternatively, all calculations can be based in particular on analog output values ​​of the corresponding acceleration sensor. When (partial) process steps are described in the following description with reference to a particular figure and the same (partial) process steps are present in another figure, the description with reference to the particular figure is equally valid unless otherwise stated. When terms like "essentially" or "approximately" are used in relation to a structural unit of a device (such as a monitoring module), the terms "essentially" or "approximately" refer to technical features that are produced within the technical tolerance limits of the respective manufacturing process.

[0138] [Figure 1] FIG. 1 illustrates a concentricity monitoring module according to a particular embodiment. [Diagram 2] FIG. 2 illustrates a concentricity monitoring tool holder module in accordance with certain embodiments. [Diagram 3] FIG. 3 illustrates a concentricity monitoring tool module in accordance with certain embodiments. [Figure 4] FIG. 4 illustrates a machine tool / machine tool set interacting with a monitoring module in accordance with certain embodiments. [Diagram 5] FIG. 5 illustrates a concentricity monitoring signal interface that communicates with a machine tool / machine tool center and monitoring module in accordance with certain embodiments. [Figure 6] FIG. 6 illustrates a flow chart of a concentricity monitoring process in accordance with certain embodiments. [Figure 7]FIG. 7 shows the arrangement of the sensor circuit board, the circuit board holder, the adjustment means for the circuit board holder, the antenna with the antenna cover and the light sensing unit in a monitoring module according to a particular embodiment. [Figure 8] FIG. 8 illustrates variables representative of acceleration at different speeds recorded by a sensor unit of a monitoring module according to a particular embodiment. [Figure 9A] FIG. 9A illustrates a schematic diagram of a method for determining the amount and angle of runout error of a monitoring module in accordance with certain embodiments. [Figure 9B] FIG. 9B illustrates total acceleration versus velocity at different positions of the sensor unit in accordance with certain embodiments. [Figure 10] FIG. 10 illustrates a quantity representing acceleration, an initial quantity representing acceleration, a total acceleration, and a threshold over which the velocity exceeds in accordance with certain embodiments. [Figure 11] FIG. 11 shows a sinusoidal signal superimposed on the variable detected by the sensor unit when the monitoring module is positioned horizontally and at different speeds. [Figure 12] FIG. 12 shows a sinusoidal signal superimposed on the variable detected by the sensor unit when the monitoring module is positioned horizontally and at different speeds. [Figure 13A] FIG. 13A illustrates the arrangement and design of the fluid channels and other optional components of the monitoring module in accordance with certain embodiments. [Figure 13B] FIG. 13B illustrates a schematic of a sensor board and a sensor unit with fluid channels according to certain embodiments. [Figure 14] FIG. 14 illustrates a turbine unit generating its own energy within a monitoring module in accordance with certain embodiments. [Figure 15] FIG. 15 illustrates a flywheel for generating its own energy within the monitoring module according to certain embodiments. [Figure 16] FIG. 16 illustrates a sequence of a calibration process involving evaluation in a monitoring module according to certain embodiments. [Figure 17]FIG. 17 illustrates a sequence of a calibration process involving evaluation at the concentricity monitoring signal interface / machine tool in accordance with certain embodiments. [Figure 18] FIG. 18 illustrates a test sequence for concentricity monitoring of a rotating tool during operation with evaluation by a monitoring module at a single test speed in accordance with certain embodiments. [Figure 19] FIG. 19 illustrates a test sequence for concentricity monitoring of a rotating tool during operation with evaluation by a monitoring module at several test speeds in accordance with certain embodiments. [Figure 20] FIG. 20 illustrates a sequence of concentricity monitoring of a rotating tool during operation with evaluation at a machine tool concentricity monitoring signal interface at several test speeds according to certain embodiments. [Figure 21] FIG. 21 illustrates a sequence of continuous process data transmission to a concentricity monitoring signal interface / machine tool in accordance with certain embodiments. [Figure 22] FIG. 22 illustrates a sequence on a machine tool during communication with a monitoring module / concentricity monitoring signal interface via IO signals in accordance with certain embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0139] 1 shows a concentricity monitoring module 10 (hereinafter also referred to as monitoring module 10) which is used to monitor the concentricity of a rotating tool WZG during operation. The concentricity monitoring module 10 comprises an essentially rotationally symmetric hollow body in which all the feeding, measuring, computing and communication devices required for the concentricity monitoring are accommodated.

[0140] The tool WZG is a tool WZG that rotates during operation (to machine a workpiece), here designed as, for example, a milling cutter. Furthermore, a tool holder WZGA and an axis S of the machine tool are shown in FIG. 1, which interact with the concentricity monitoring module 10 during concentricity monitoring. The tool holder WZGA is shown here outside the axis S, but can also be integrated into the axis S when the concentricity monitoring module 10 is inserted into the axis S of the machine tool to monitor the concentricity of the tool WZG. When the monitoring module 10 rotates together with the axis S and the tool WZG to machine a workpiece, the concentricity of the monitoring module 10 and indirectly the concentricity of the tool WZG (or the concentricity of the combination of the monitoring module 10, the tool holder WZGA and the tool WZG) is monitored. If a concentricity error is present, this indicates, for example, a face contact or taper contact failure caused by chips adhering to the axis S, in particular the tool holder WZGA and thus the concentricity monitoring module 10 of the axis S.

[0141] As can be seen in the cross-sectional view of the concentricity monitoring module 10 according to Fig. 1, the concentricity monitoring module 10 has an essentially cylindrical body that can be rotationally symmetrical about a rotation axis 20. The concentricity monitoring module 10 comprises a tool interface 12 designed to receive a tool WZG. In this example, the tool interface 12 comprises a receptacle that mates with a corresponding counterpart of the tool WZG (shown in Fig. 1 as a double arrow between the interface 12 and the tool WZG).

[0142] Similarly, the concentricity monitoring module 10 has a tool holder interface 14 that mates with a corresponding holder of the tool holder WZGA (shown in FIG. 1 as a double arrow between the interface 14 and the tool holder MEWZGA). Thus, the concentricity monitoring module 10 can be coupled to the tool holder WZGA and the tool WZG via the interfaces 12, 14, either by the manufacturer or by an operator. When the tool holder WZGA, the concentricity monitoring module 10 and the tool WZG are inserted together in an assembled state (shown in FIG. 1 as a double arrow between the axis S and the tool holder WZGA) into the axis S of a machine tool, the tool holder WZGA, the concentricity monitoring module 10 and the tool WZG rotate together around the axis of rotation 20 of the concentricity monitoring module 10 to machine a workpiece. The speed is determined by the axis S of rotation.

[0143] The electronic unit is arranged in the monitoring module 10 and comprises a first sensor unit 16, a second optional sensor unit B, a computing device 22, a communication device 24 and a power supply unit V. As shown in Fig. 1 by the arrows from the energy supply unit V to the corresponding components, the energy supply unit V supplies the first sensor unit 16, the second sensor unit B, the computing device 22 and the communication device 24 with the electrical energy required to perform the measurement, calculation and communication operations described in this disclosure that are necessary for the concentricity monitoring of the tool WZG.

[0144] Communications between the computing device 22 and the first sensor unit 16 in the concentricity monitoring module 10, and between the second sensor unit B and the communication device 24, are carried out via communication lines shown by dashed arrows in FIG. 1, here exemplified by an SPI bus.

[0145] In order to monitor the concentricity of the concentricity monitoring module 10 and thus of the tool WZG, the centrifugal acceleration of the rotation plane E is observed by the first sensor unit 16 during the rotation of the concentricity monitoring module 10 around the rotation axis 20 either before, after and / or during machining of the workpiece. For this purpose, the first sensor unit 16 comprises a two-axis acceleration sensor arranged in the concentricity monitoring module 10 to detect accelerations in an essentially vertically oriented xy-plane (rotation plane E). This rotation plane E is shown in FIG. 1 as passing through the concentricity monitoring module 10.

[0146] To achieve such acceleration detection, the first sensor unit 16 is arranged at the rotation center of the concentricity monitoring module 10 such that the rotation axis of the concentricity monitoring module 10 passes through the sensor unit 16. As shown in FIG. 1, the rotation axis 20 and the inertial axis 18 of the acceleration sensor of the first sensor unit 16 are ideally substantially coaxial. Due to this arrangement of the inertial axis of the sensor unit 16 in the z direction, the other inertial axes of the sensor unit 16 in the x and y directions are essentially orthogonal to the rotation axis 20, so that acceleration can be measured in the plane E. In this example, the sensor unit 16 has only two sensitive inertial axes, namely the x and y directions. The third inertial axis, namely the inertial axis in the z direction, is less sensitive in this example (accelerations along this axis are not detected) and therefore has in particular the function of accurately aligning the sensor unit 16 with the rotation axis 20. However, in other examples, the sensor unit 16 can be designed to be able to measure accelerations in the z direction as well.

[0147] Regarding the centrifugal acceleration a,

number

number

number

[0148] However, if the inertial axis of the sensor unit 16 coincides exactly with the axis of rotation 20 of the monitoring module 10 and extends coaxially with the axis of rotation D of the shaft S (see also FIG. 4), then the radial distance is zero (r=0), so the axial centrifugal acceleration will be zero even if the speed of S is relatively high. This is therefore the case for optimal alignment of the sensor unit 16 in the absence of concentricity errors.

[0149] However, if there is a clamping error of the tool holder WZGA relative to the axis S, for example due to chip bite when inserting the tool holder WZGA into the axis S, an offset of the monitoring module 10 and therefore of the sensor unit 16 relative to the axis of rotation D of the axis S occurs. The radial distance is then no longer zero (r≠0) and a centrifugal acceleration acts on the sensor unit 16 during rotation. During rotation, the sensor unit 16 records variables ax,ay representative of the acceleration in the x-direction and in the y-direction and transmits these to the computing device 22 in the form of digital sensor values ​​which in particular characterize the acceleration in the respective direction or which can be converted to an acceleration in the respective direction in the computing device 22. A total acceleration value is determined by the computing device 22 on the basis of the variables ax,ay representative of the acceleration in the x-direction and in the y-direction and is calculated based on a threshold value.

number

[0150] The optional further sensor unit B is exemplarily designed as a one-axis acceleration sensor, with its sensing axis arranged radially perpendicular to the axis of rotation (20) and set to detect at least one variable representative of further acceleration (hereinafter also referred to as further acceleration variable). However, the invention is not limited thereto. For example, the optional sensor unit B can also be designed in the same way as the first sensor unit B, i.e. as a two-axis acceleration sensor set to detect a further variable representative of acceleration in two mutually perpendicular directions (hereinafter also referred to as further acceleration variable). The further sensor unit B can be designed as a one-axis or two-axis acceleration sensor measuring one or two variables representative of further acceleration, so that

number

[0151] Another sensor unit B is arranged in the concentricity monitoring module 10 so as to detect these other acceleration variables, namely the centrifugal acceleration, in a plane E radially spaced from the axis of rotation (20) and oriented perpendicularly to the axis of rotation 20 of the monitoring module. In particular, the velocity is detected during the detection of the variables ax, ay representing the acceleration, for example by converting them into n when the angular velocity is known and by calculating the rotational velocity n, according to the formula

number

[0152] 2 shows a concentricity monitoring tool attachment module 26 (hereinafter also referred to as monitoring module 26) which monitors the concentricity of a rotating tool WZG during operation. The concentricity monitoring tool attachment module 26 is preferably designed as a hollow cylinder and comprises an essentially rotationally symmetric hollow body in which all feeding, measuring, computing and communication devices required for concentricity monitoring are accommodated.

[0153] The tool WZG is a tool WZG that rotates during operation (to machine a workpiece), here designed, for example, as a milling cutter. Furthermore, FIG. 2 shows an axis S (see also FIG. 4) of the machine tool, which interacts with the concentricity monitoring tool holder module 26 during concentricity monitoring. When the concentricity monitoring tool holder module 26 rotates together with the axis S and the tool WZG to machine a workpiece, it monitors the concentricity of the tool WZG. If a concentricity error of the tool WZG is present, this indicates, for example, a surface contact failure of the concentricity monitoring module 10 of the axis S caused by chips adhering to the concentricity monitoring module 10 of the axis S.

[0154] The concentricity monitoring tool holder module 26 further comprises a tool holder WZGA, through which the concentricity monitoring tool holder module 26 is inserted into the spindle S of the machine tool. In this example, the tool holder WZGA is designed as a hollow shank taper (HSK) and is rigidly coupled to the concentricity monitoring tool holder module 26.

[0155] Otherwise, the concentricity monitoring toolholder module 26 comprises identical components: a first sensor unit 16 (with a non-sensing inertial axis 18 in the Z direction), an optional second sensor unit B, a computing device 22 and a communication device 24. In terms of these components, the concentricity monitoring toolholder module 26 has the same functions as the concentricity monitoring module 10 and is similarly arranged to be operatively connected to each other (for communication and power supply), therefore please refer to the description in relation to FIG. 1 including the description regarding the observation of the centrifugal acceleration in plane E.

[0156] 3 shows a concentricity monitoring tool module 28 (hereinafter also referred to as monitoring module 28) which monitors the concentricity of the rotating tool WZG during operation. The concentricity monitoring tool module 28 preferably comprises an essentially rotationally symmetric hollow body designed as a hollow cylinder and in which all feeding, measuring, computing and communication devices required for concentricity monitoring are accommodated.

[0157] The tool WZG is a tool WZG that rotates during operation (to machine a workpiece), here designed, for example, as a milling cutter. Furthermore, FIG. 2 shows an axis S (see also FIG. 4) of the machine tool, which interacts with the concentricity monitoring tool holder module 26 during concentricity monitoring. When the concentricity monitoring tool holder module 26 rotates together with the axis S and the tool WZG to machine a workpiece, it monitors the concentricity of the tool WZG. If a concentricity error of the tool WZG is present, this indicates, for example, a surface contact failure of the concentricity monitoring module 10 of the axis S caused by chips adhering to the concentricity monitoring module 10 of the axis S.

[0158] 2, the concentricity monitoring tool module 28 also further comprises a tool holder WZGA, through which the concentricity monitoring tool module 28 is inserted into the spindle S of the machine tool. In this example, the tool holder WZGA is designed as a hollow shank taper (HSK) and is rigidly coupled to the concentricity monitoring tool module 28.

[0159] In contrast to the monitoring modules 10 and 26 shown in figures 1 and 2, the concentricity monitoring tool module 28 comprises a tool WZG, which are permanently connected to each other and inserted as a complete unit together with the tool holder WZGA in the axis S. Otherwise, the concentricity monitoring tool module 28 comprises identical components: a first sensor unit 16 (with a non-sensing inertial axis 18 in the Z direction), an optional second sensor unit B, a computing device 22 and a communication device 24. In terms of these components, the concentricity monitoring tool module 28 has the same functions as the concentricity monitoring module 10 and is similarly arranged to be operatively connected to each other (for communication and power supply), therefore please refer to the explanation in relation to figure 1, including the explanation regarding the observation of the centrifugal acceleration in the plane E.

[0160] With reference to Fig. 4, a machine tool WZM is described which is exemplarily designed as a multi-axis machining centre BA. The concentricity of a tool WZG rotating during operation is monitored by the machine tool WZM in cooperation with one of the monitoring modules 10, 26 or 28. The example of Fig. 4 is shown using a concentricity monitoring tool module 28. However, it should be noted here that the concentricity monitoring tool module 28 only represents one of the monitoring modules 10, 26, 28 and that the machine tool WZM can also interact with the concentricity monitoring module 10 and the concentricity monitoring tool mounting module 26 during operation.

[0161] The machine tool WZM in Fig. 4 comprises, by way of example, an axis S which can be moved in the working space of the machine tool WZM in three orthogonal directions X, Y, Z and can be rotated around the Z axis. Such a rotation of the axis S of the machine tool WZM about a rotation axis D (extending in the z direction in the plane of the paper of Fig. 4) is typically performed during machining of a workpiece by the machine tool WZM.

[0162] Furthermore, the machine tool comprises a control device 32, a communication device 30 and a tool changer (not shown) which is arranged to accommodate at least the monitoring modules 10, 26 and 28. In this way, the modules 10, 26, 28 (monitoring modules 10 and 26 are in particular already coupled to the tool WZG) can be exchanged at any time to the shaft S before or after machining of the workpiece, in particular for checking the concentricity of the workpiece during a subsequent machining step.

[0163] For this purpose, the control device 32 of the machine tool WZM is also configured to set the speed of the axis S. Furthermore, the control device 32 is configured to control the communication with the monitoring module 28 via the communication device 30. For this purpose, the communication device 30 of the machine tool WZM communicates by wire with a data transmission unit 34. The data transmission unit 34 is coupled to the communication device 24 of the monitoring module 28 via a wireless link and is configured to receive signals and data, such as the variables ax, ay and other variables described in the context of the present disclosure, from the communication device 24 of the monitoring module 28 and to transmit them to the machine tool WZM, more precisely to its communication device 30.

[0164] In alternative variants not shown in Fig. 4, the functions of the data transmission unit 34 are included in the communication device 30 of the machine tool WZM. The data transmission unit 34 is therefore omitted as a physical unit. In these cases, data and signals are transmitted directly between the machine tool and the monitoring module 28, preferably by radio or infrared signals.

[0165] To monitor the concentricity, the sensor unit 16 of the monitoring module 28 records variables ax,ay representative of acceleration, as explained with reference to Fig. 1. The variables ax,ay are transmitted via the communication device 24 (according to Fig. 4 via the data transmission unit 34 and the communication device 30 of the machine tool) to the computing device 32 of the machine tool. The computing device 32 determines a total acceleration atot from the variables ax,ay and compares this with a threshold value. If the total acceleration atot exceeds the threshold value, the machine tool WZM determines that the monitoring module 28 has a concentricity error.

[0166] Fig. 5 shows a concentricity monitoring signal interface SGS with a communication device 36 and a computing device 38. The concentricity monitoring signal interface SGS is configured to operatively interact with a machine tool WZM (e.g., the machine tool of Fig. 4) and one of the monitoring modules 10, 26, 28 to monitor the concentricity of a rotating tool WZG during operation. The example of Fig. 5 is shown using the concentricity monitoring tool module 28. However, here the concentricity monitoring tool module 28 only represents one of the monitoring modules, and the concentricity monitoring signal interface SGS can similarly interact with the concentricity monitoring module 10 and the concentricity monitoring tool holder module 26 during operation.

[0167] The computing device 38 of the concentricity monitoring signal interface SGS is arranged to control the communication with the monitoring module 28 via the communication device 36. For this purpose, the communication device 36 of the runout monitoring signal interface SGS provides wired communication by data transmission. The data transmission unit 34 is coupled to the communication device 24 of the monitoring module 28 via a wireless link, It is set up so as to receive signals and data, such as the variables ax, ay and other variables described in the context of the present disclosure, from the communication device 24 of the monitoring module 28 and to transmit them to the runout monitoring signal interface SGS, and more precisely to its communication device 36.

[0168] In alternative variants not shown in Fig. 5, the functions of the data transmission unit 34 are included in the communication device 36 of the runout monitoring signal interface SGS. The data transmission unit 34 is therefore omitted as a physical unit. In these cases, data and signals are transmitted directly between the concentricity monitoring signal interface and the monitoring module 28, preferably by radio or infrared signals.

[0169] Furthermore, the computing device 38 of the concentricity monitoring signal interface SGS is configured to control the communication with the machine tool WZM via a wired communication interface of the communication device 36. This "communication connection", here exemplified as a fieldbus, is indicated in Figure 5 by a solid double arrow between the communication device 36 of the runout monitoring signal interface SGS and the communication device 30 of the machine tool WZM.

[0170] The concentricity monitoring signal interface SGS is configured to receive, via the communication device 36, values ​​ax,ay representative of the acceleration recorded by the monitoring module 28 of the plane E. The calculation device 38 of the concentricity monitoring signal interface SGS is further configured to determine a total acceleration atot from the variables ax,ay received from the monitoring module 28. The total acceleration atot is compared with a threshold value. If the total acceleration atot exceeds the threshold value, the concentricity monitoring signal interface SGS determines that the monitoring module 28 has a concentricity error.

[0171] The computing device 38 of the concentricity monitoring signal interface SGS is configured and intended to transmit a signal to the machine tool WZM whether a concentricity error is present or not. This is done via a wired communication connection between the communication device 36 of the concentricity monitoring signal interface SGS and the communication device 30 of the machine tool WZM, via which the concentricity monitoring signal interface SGS provides a test signal (OK / NOK) to the machine tool WZM that a concentricity error is present (NOK) or that a concentricity error is not present (OK).

[0172] With reference to Fig. 6, a method for monitoring the concentricity of a tool rotating in a machine tool is described. All process steps can be performed by the machine tool WZM as described with reference to Fig. 4. Alternatively, some of the process steps can be performed by the monitoring modules 10, 26, 28 and / or some of the process can be performed by the runout monitoring signal interface SGS. In particular, the determination of the total acceleration atot, the comparison of the total acceleration with a threshold value and the determination of whether a concentricity error exists (these three steps are also referred to as "evaluation" in the following) can be performed by the monitoring modules 10, 26, 28 as well as by the concentricity monitoring signal interface SGS and the machine tool WZM.

[0173] As shown in Fig. 6, the concentricity monitoring method comprises a first step (i) in which the monitoring module 10, 26, 28, which rotates during operation, or the monitoring module 10, 26, which rotates during operation and the tool WZG, are automatically inserted into the axis S of the machine tool WZM. In particular, the axis S is brought close to the tool changer of the machine tool WZG in order to exchange one of the monitoring modules 10, 26, 28 contained in the tool changer of the machine tool WZG into the axis S. If this is the monitoring module 10 or the monitoring module 26, these are usually already coupled to the tool WZG and the tool holder WZGA (monitoring module 10) or the tool WZG (monitoring module 26).

[0174] In a second step (ii), the axis S of the machine tool WZM is rotated at a predefined speed, which (also the test rotation speed) is set by the machine tool (or by a user of the machine tool) and transmitted by the machine tool, if necessary via the concentricity monitoring signal interface SGS, to the monitoring module 10, 26, 28 or directly to the concentricity monitoring signal interface SGS, in case the evaluation is performed in the monitoring module 10, 26, 28 or in the concentricity monitoring signal interface SGS.

[0175] In a third step (iii), the variables ax, ay representative of the acceleration are detected or received in a plane E oriented substantially perpendicular to the axis of rotation 20 of the monitoring module 10, 26, 28 rotating at a predefined speed. This detection is performed in particular by one of the monitoring modules 10, 26, 28 as explained with reference to Fig. 1. The corresponding explanation of Fig. 1 is therefore also valid here. If the machine tool WZM or the concentricity monitoring signal interface SGS executes the concentricity monitoring process, in a third step the acceleration variables ax, ay are transmitted as raw data from the monitoring module 10, 26, 28 to the machine tool / concentricity monitoring signal interface SGS and received there.

[0176] The above-mentioned evaluation then carries out steps (iv) to (vi), in a fourth step (iv) determining a total acceleration atot based on the detection variables ax, y representing the acceleration, in a fifth step (v) comparing the total acceleration atot with a threshold value depending on the rotational speed of the rotating monitoring module 10, 26, 28 during detection of the variables ax, ay representing the acceleration, and in a sixth step (vi) determining that a concentricity error of the rotating monitoring module 10, 26, 28 and / or the rotating tool WZG exists if the total acceleration atot is greater than the threshold value.

[0177] In particular, if the evaluation (steps (iv) to (vi)) is performed in the monitoring module 10, 26, 28 or in the concentricity monitoring signal interface SGS, an optional step (vii) can follow, in which case the monitoring module 10, 26, 28 or the concentricity monitoring signal interface transmits an SGS signal to the machine tool WZM via the above-mentioned communication devices 24 and / or 36 (see also Figure 5) regardless of whether a concentricity error of the monitoring module 10, 26, 28 or the concentricity monitoring signal interface is present or not.

[0178] The present disclosure also relates to a computer program product (not shown) comprising instructions for causing a machine tool (as described with reference to FIG. 4) to perform the process steps (i) to (vi) of a concentricity monitoring process. According to another example, the computer program product comprises instructions for causing a monitoring module 10, 26, 28 to perform the method steps (iii) to (vi) of a concentricity monitoring method. According to yet another example, the computer program product comprises instructions for causing a runout monitoring signal interface (SGS) to perform the method steps (iii) to (vi) of a runout monitoring method. These various variants may also be combined in a single computer program product.

[0179] Further optional features and designs of the monitoring modules 10, 26, 28 when recording and / or evaluating the variables ax, ay representing acceleration and further process variables related to concentricity monitoring as well as further (partial) process aspects of the concentricity monitoring method are described below with reference to figures 7 to 22. The features described with reference to further optional steps of the concentricity monitoring method can also be transferred to the monitoring modules 10, 26, 28 and vice versa. Whenever the first sensor unit 16 (with inertial axis 18 in the z direction), the second sensor unit B, the energy supply unit V, the computing device 22 or the communication device 24 are mentioned in the description of figures 7 to 22, these descriptions refer to the corresponding components of each of the monitoring modules 10, 26 and 28.

[0180] FIG. 7 shows a cross-sectional view of the monitoring module 10, 26, 28, the tool holder WZGA and the axis S of the machine tool WZM (see also FIG. 4) in a clamped state, i.e. immediately before exchanging the module 10, 26, 28 from the tool changer to the axis S. This cross-sectional view shows the first sensor unit 16 and the further optional sensor unit B arranged on a sensor board 40. In this example, the sensor board 40 is connected to a board holder 42 via a vertical strut. The circuit board holder 42 is mounted floating in the monitoring module 10, 26, 28, so that the exact type of suspension is not shown in FIG. 7. FIG. 7 also shows two threaded pins 44 serving as adjustment means. Furthermore, FIG. 7 shows that the monitoring module 10, 26, 28 comprises two optional antenna covers 46 and two optional antennas 48 (for the sake of further clarity, the references 46, 48 are shown only once in FIG. 7). Finally, the monitoring module 10, 26, 28 comprises a photosensitive unit PE having a photosensitive surface 50 located at the outer periphery of the monitoring module 10, 26, 28 and directed radially outwards.

[0181] The antenna 48 and the antenna cover 46 cooperate to form an antenna unit. Here, the antenna cover 46 is, by way of example, arranged directly on the outer periphery of the monitoring module 10, 26, 28, forming, for example, a section of the monitoring module 10, 26, 28, which is made of a body and / or a different material manufactured separately from the rest of the body of the monitoring module 10, 26, 28. The antenna 48 is arranged in the monitoring module 10, 26, 28 between the antenna cover 46 and the rotation shaft 20, the horizontal position of the antenna 48 shown in FIG. 7 is merely exemplary, the antenna 48 is further arranged to face the rotation shaft 20. The antenna cover 46 extends in the axial direction of the rotation shaft 20 by four times the antenna 48 in this example. In other variants, the antenna cover 46 can extend 2 to 10 times in the axial direction of the rotation shaft 20, whereby all integer intermediate values ​​are included as alternative possible range limits. The antenna cover 46 therefore covers the antenna 48 on the outside to protect the antenna 48 from damage, dirt and cooling lubricants. The antenna cover 46 may comprise at least a majority or entirely non-conductive material to avoid impeding the propagation of radio waves. The antenna cover may comprise, for example, plastic, glass, ceramic, and / or a molding compound.

[0182] A set screw 44 is used to position the floating suspended circuit board holder 42, and thus the sensor unit 16 or, in this example, its inertial Z-axis 18, directly at the center of rotation of the monitoring module 10. The threaded pin 44 thus serves to balance the sensor unit 16, so that the sensor unit 16 or its inertial Z-axis is at least approximately coaxially aligned with the axis of rotation 20 of the monitoring module 10, 26, 28. This centering is preferably performed already during the manufacture of the monitoring module 10, 26, 28.

[0183] Further threaded pins 45 can be inserted into the body of the monitoring modules 10, 26, 28 via radial threaded holes, not shown in FIG. 7, which allows fine-tuning of the sensor unit 16, which can also be done in particular by the user. The radial threaded holes are designed to accommodate a number of threaded pins 45 of different weights (the different weights of the threaded pins 45 are shown in FIG. 7 by different sizes), all of which can accommodate additional mass. As a result, for example, depending on the optional components used and the subsequent resulting monitoring modules 10, 26, 28 weight ratio or after a change of the tool WZG (this applies in particular to the monitoring modules 10 and 26 according to FIGS. 1 and 2), a balance can be made for each of the monitoring modules 10, 26, 28.

[0184] FIG. 7 also shows that another sensor unit B arranged on the sensor board 40 is arranged radially away from the sensor unit 16. Here, the distance between the another sensor unit B and the sensor unit 16 perpendicular to the axis is about 75% of the radius of the monitoring module 10, 26, 28. However, the present disclosure is not limited thereto. The distance may be in the range of 3% to 90% (all integer intermediate values ​​are included as other possible range limits). It is only important that the another sensor unit B is not aligned coaxially with the rotation axis 20, because in this position a reliable determination of the rotation speed is not possible.

[0185] The measurement principle used for concentricity monitoring is explained in more detail with the aid of actual measurement data with reference to figure 8. To illustrate this, the (absolute) digital output values ​​of the sensor unit 16 are shown in two diagrams in the x-direction (ax, top diagram) and in the y-direction (ay, bottom diagram) at different speeds over a number of measurement values.

[0186] In the measurement according to Fig. 8, the monitoring modules 10, 26, 28 are arranged perpendicular to the axis S, so that the axis of rotation 20 of the monitoring modules 10, 26, 28 follows a vertical direction and a variable representing the acceleration (output value of the sensor) is recorded by the sensor unit 16 in a plane E oriented perpendicular to the vertical direction, i.e. in the horizontal plane of rotation of the monitoring modules 10, 26, 28. The test speeds are approximately 500 rpm, 1000 rpm, 1500 rpm and 2000 rpm, the corresponding sections of Fig. 8 showing the output values ​​of the sensor unit 16 at these test speeds are delimited by vertical dashed lines. The measurement range of the sensor unit 16 is here exemplarily ±2 g, the resolution (sensitivity) of the sensor unit 16 is here exemplarily 1024 digital values ​​per g (corresponding to 10 bits) and the sampling rate is exemplarily 0.5 kHz.

[0187] FIG. 8 differs in particular in that the upper diagram shows the output values ​​of the sensor unit 16 in the x-direction (ax) and the lower diagram shows the output values ​​of the sensor unit 16 in the y-direction (ay). Furthermore, three different curves are shown for each axis. The solid curves represent the output values ​​of the sensor unit 16 when the inertial Z-axis 18 of the sensor unit 16 is aligned as coaxially as possible with the rotation axis 20 of the monitoring module 10, 26, 28. The dashed curves represent the output values ​​of the sensor unit 16 when the inertial Z-axis 18 is located at a radial distance of about 10 μm from the rotation axis 20 due to the tilt / eccentricity of the monitoring module 10, 26, 28. Finally, the dashed and dotted curves represent the output values ​​of the sensor unit 16 when the inertial Z-axis 18 is located at a radial distance of about 30 μm from the rotation axis 20 due to the tilt / eccentricity of the monitoring module 10, 26, 28.

[0188] As can be seen from the top diagram of FIG. 8, the sensor unit 16 is in fact arranged at least approximately coaxially with the axis of rotation 20 of the monitoring module 10, 26, 28 in the x-direction, which is complicated by the tolerances in the manufacture of the sensor unit 16 as well as the assembly and manufacturing tolerances of the monitoring module 10, 26, 28. As a result, the acceleration in the x-direction does not increase with increasing speed. The acceleration value ax therefore remains constant up to a speed of about 2000 rpm, and no increase in acceleration can be measured. In contrast, the dashed and dotted curves in the top diagram of FIG. 8 show the behavior of the acceleration value ax when the sensor unit is 10 μm or 30 μm away from the axis of rotation 20 in the x-direction. At a speed of 500 rpm, there is a slight change in the acceleration value ax at 10 μm and 30 μm. In particular, in the case of a central offset of the sensor unit 16 in the x-direction of 30 μm (dotted curve), the acceleration value ax increases further as the speed increases, so that at a speed of about 2000 rpm, an ax value of more than 2200 is already reached, which corresponds to an additional acceleration of more than 1 g (in this example, about 1.3 m / s 2 ) As shown in the lower diagram of FIG. 8, the acceleration curves in the y direction for a central offset of 10 μm (dashed curve) and for a central offset of 30 μm in the y direction (dotted curve) behave almost similarly to the measurements of the corresponding central offset in the x direction, for which reasons see now the explanation of the upper diagram of FIG. 8. The solid lines in the lower diagram of FIG. 8 represent the acceleration values ​​recorded in the y direction by the sensor unit 16. These ay values ​​still remain almost always close to zero at a relatively low speed of about 500 rpm (a sensor value of 2050 corresponds to about 0 g), but increase with increasing speed at about 2000 rpm, which is about 0.5 m / s 2 This is a relatively low acceleration value, but characterizes the fact that the sensor unit 16 was not exactly coaxial with the axis of rotation 20 during the measurement.

[0189] Since accurate concentricity is very important in high-precision applications in the field of workpiece machining, such "imbalance" of the sensor unit 16 with respect to the rotary axis 20 due to slight radial and / or angular offsets (still within the corresponding tolerance limits) can be compensated for, for example, by performing a calibration. In this calibration run, initial variables ax, ay (hereinafter also called initial (acceleration) variables) representing accelerations are measured by the sensor unit 16 installed in the monitoring module 10, 26, 28. The recording of the variables ax_initial, ay_initial representing the initial accelerations is essentially performed similarly to the recording of the variables ax, ay representing the accelerations (see also the description of FIG. 1). The initial variables ax_initial, ay_initial are stored in the memory of the monitoring module 10, 26, 28 together with the test speed being acquired. Alternatively, the initial variables ax_initial, ay_initial can be transmitted via the communication device 24 of the monitoring module 10, 26, 28 to the concentricity monitoring signal interface and / or the machine tool WZM and stored in a local memory.

[0190] The calibration, which can be performed at one or more test speeds, is performed separately from the normal operation of machining a workpiece with the machine tool WZM when the axis S is elevated, i.e. when an essentially constant test speed prevails or with deviations of up to 10% from the specified test speed. In case of performing several calibrations for different speeds, a speed-dependent function of the initial variables ax_initial, ay_initial is generated, which is stored in the memory of the monitoring module 10, 26, 28 and / or the concentricity monitoring signal interface SGS and / or the machine tool WZM.

[0191] Further, as an example, the calibration is performed under ideal conditions monitored by the manufacturer, whereby the axis S and the monitoring modules 10, 26, 28 are clean and there are no chips within the effective range of these components, so that the monitoring modules 10, 26, 28 are ideally positioned flat relative to the axis S.

[0192] The determined initial values ​​ax_initial, ay_initial are taken into account in the form of offset values ​​when determining the total acceleration atot. The total acceleration value atot is calculated in relation to the total acceleration a_resulting obtained as follows:

number

[0193] Fig. 9A shows how the determined total acceleration is determined from the acceleration components ax, ax_initial, ay, ay_initial and, consequently, the amount r and angle of the radial acceleration a_resulting taking into account the initial acceleration values ​​ax_initial and ay_initial and the amount r and angle of the run-out error. A unit circle divided into four quadrants is shown in Fig. 9A, with the axis of rotation 20 extending from the main axis S in the direction of the tool WZG through the centre of the unit circle.

[0194] The amount of runout error r (μm) and the acceleration variable

number

[0195] In Fig. 9B, the total acceleration atot is shown as output value of the calibrated sensor unit 16 over various rotation speeds and at various positions of the inertial Z-axis 18 of the sensor unit 16 relative to the rotation axis of the monitoring module 10, 26, 28. The measurement range of the sensor unit 16 is exemplarily ±2g, the resolution (sensitivity) of the sensor unit 16 is exemplarily 1024 digital values ​​per g (corresponding to 10 bits) and the sampling rate is exemplarily 0.5 kHz. All calculations underlying Fig. 9B are performed using the variables ax, ay, ax_initial and ay_initial averaged over 8 rotations of the monitoring module 10, 26, 28 / axis S.

[0196] The solid line in FIG. 9B (first from the bottom) indicates the total acceleration atot when the sensor unit 16 is in the "outer center 10 μm" position. The dashed curve in FIG. 9(b) (second from the bottom) indicates the total acceleration atot when the sensor unit 16 is in the "outer center 30 μm" position. The dashed line in FIG. 9B (third from the bottom) indicates the total acceleration atot when the sensor unit 16 is in the "center 10 μm" position. The dashed double-dotted curve in FIG. 9B (first from the top) indicates the total acceleration atot when the sensor unit 16 is in the "center 10 μm" position. The calculation results of the total acceleration are summarized in the table below. [Table 3]

[0197] As can be seen from the table combined with FIG. 9B, the total acceleration at the “center 30 μm” position in particular increases to a value of 114 at a speed of 1500 rpm and to a value of 206 at 2000 rpm, which corresponds to approximately 0.2 g.

[0198] 9B also shows that the total acceleration atot increases with increasing speed, regardless of the exact positioning or center offset of the sensor unit 16. For this reason, the threshold against which the total acceleration atot is compared to check whether there is a concentricity error of the monitoring module 10, 26, 28 is not a static threshold, but a "dynamic" threshold that increases with increasing speed.

[0199] This is shown in Fig. 10, where the acceleration variables ax, ay, ax_inital, ay_initial and atot (corresponding to a_reSulting) as well as the threshold value SW are plotted over the speed of the monitoring module 10, 26, 28. Fig. 10 also shows that all these variables increase as the speed increases. The initial variables ax_inital, ay_initial representing the acceleration have lower acceleration values ​​than the variables ax, ay representing the acceleration according to the sensitivity direction, respectively, because there is a large constant eccentricity / tilt of the sensor unit 16 during the measurement of the variables ax, ay in the monitoring mode of the monitoring module 10, 26, 28 compared to the calibration run. However, the calculated total acceleration atot (corresponding to a_reSulting) is below the threshold value SW at all speeds, i.e. within the acceptable range, so that in this evaluation there is no concentricity error, but the concentricity of the monitoring module 10, 26, 28 is OK (IO). If such an evaluation is performed in the monitoring module 10, 26, 28, the result can be transmitted as a test signal IO to the machine tool WZM and / or to the concentricity monitoring signal interface SGS. Alternatively, the raw data of the measurement variables ax_initial, ay_initial can also be transmitted to the machine tool WZM and / or to the concentricity monitoring signal interface SGS and evaluated there.

[0200] In determining the variables ax, ay, ax_inital, ay_initial, it is important that the component performing the evaluation knows the exact rotational speed at which these variables were determined, since these variables are quadratic functions. Several options are available for this within the scope of this disclosure.

[0201] A first possibility is to determine the rotation speed using another acceleration variable (or a single other acceleration variable) determined by another sensor unit B during acquisition of the variables ax, ay representing the acceleration (and during the execution of the calibration during acquisition of the initial variables ax_inital, ay_initial). The principle of detection of the rotation speed by another sensor unit B is explained using Fig. 1. The explanation there also applies here.

[0202] A second possibility, in which the additional optional sensor unit B for speed detection can be omitted, is described with reference to figures 11 and 12. The sensor unit 16 has a measurement range of ±2 g and a resolution of 1024 digital values ​​per g. The sampling rate is 1 kHz. In the measurement results shown in figures 11 and 12, the monitoring modules 10, 26, 28 are oriented horizontally. As a result, due to the acceleration due to gravity acting on the monitoring modules 10, 26, 28 during the measurement, sinusoidal signals are superimposed on the measured real variables (e.g. ax, ay, ax_initial, ay_initial).

[0203] FIG. 11 shows such a superposition of signals, where the output values ​​(ax) of the sensor unit 16 are shown in the x-direction at different speeds. Similarly, FIG. 12 shows such a superposition of signals, where the output values ​​(ay) of the sensor unit 16 are shown in the y-direction at different speeds. The amplitude of the sinusoidal vibration superimposed on the measurement variable corresponds approximately to the acceleration due to gravity. This is particularly true for a speed of approximately 1000 rpm, where (see FIGS. 11 and 12 ) there is an amplitude of approximately 1000, which corresponds approximately to an acceleration due to gravity of approximately 1 g. FIG. 11 also shows that the average value of the sinusoidal signal increases as the speed increases. Thus, at approximately 1000 rpm the average value amounts to a digital sensor value of 2075, while at approximately 1500 rpm the average value rises to a digital sensor value of 2115 and at approximately 2000 rpm the digital sensor value rises to approximately 2155.

[0204] As can be seen from Figures 11 and 12, the frequency of the sinusoidal signal changes with increasing speed. Thus, the frequency correlates with the speed, and in particular, the frequency corresponds to the speed. Thus, the frequency of the sinusoidal vibration superimposed on the actual measurement variable when the monitoring module 10, 26, 28 is aligned horizontally can be used to infer the rotation speed when the actual measurement variable is detected using known calculation methods.

[0205] The light-sensing unit PE with the light-sensitive surface 50 described with reference to FIG. 7 utilizes yet another possibility of determining the speed during the detection of the acceleration variables ax, ay, ax_initial, ay_initial. This is optical speed detection by means of a natural light pattern that is generated during the detection. This light pattern is generated by the rotation of the monitoring module 10, 26, 28 and is converted by the computing device 22 of the monitoring module 10, 26, 28 into a voltage pattern that is repeated with each rotation. The fundamental frequency of the voltage pattern or the underlying light pattern is determined. This fundamental frequency corresponds to the speed of the monitoring module 10, 26, 28 when the acceleration variables ax, ay, ax_initial, ay_initial are detected by the sensor unit 16. If the ambient light is insufficient in the application situation of the monitoring module 10, 26, 28, the light-sensing unit PE is an IR photodiode. In this case, it is not the ambient light that is detected but infrared light from which the speed can be determined. This infrared light is emitted by an infrared transmitting / receiving module of the machine tool WZM. The transmitter comprises an IR LED.

[0206] Finally, the machine tool WZM can also signal the exact test speed (specified as speed by the control device 32 of the axis S) to the monitoring module 10, 26, 28 and / or the concentricity monitoring signal interface SGS. This is particularly useful if the evaluation of the concentricity monitoring is performed in the monitoring module 10, 26, 28 or in the concentricity monitoring signal interface SGS.

[0207] FIG. 13A shows a cross-sectional view of an example of a monitoring module 10, 26, 28 with an optional fluid channel FK. A fluid channel is also shown in the center of the additional component shaft S and the tool holder WZGA shown in FIG. 13A. In particular, the tool WZG of the monitoring module 28 can also have such a fluid channel. The tool WZG, which can be coupled to the monitoring module 10, 26, can also have a fluid channel. During machining of the workpiece, for example, the necessary coolant and / or lubricant is supplied to the machining point via these fluid channels via the shaft S, the monitoring module 10, 26, 28 and the tool WZG in order to prevent damage to the tool WZG and the workpiece and to achieve even better machining results.

[0208] If, as in the present example, the sensor unit 16 is aligned at least approximately coaxially with the rotation axis 20 of the monitoring module 10, 26, 28, the flow of the cooling lubricant is not guided exactly centrally to the center of the monitoring module 10, 26, 28 in the example shown in Fig. 13A. As shown in Fig. 13A, the fluid channel FK, which initially starts from the center of the surface of the monitoring module 10, 26, 28 facing the axis S, is divided by the cooling lubricant distributor into two subsections of the fluid channel FK just before the sensor unit 16. As a result, the cooling lubricant is sent to the two subsections of the fluid channel FK through the machine tool WZM with the monitoring module 10, 26, 28 during the machining of the workpiece and is thus guided around the sensor unit. The fluid channel FK and its subsections are designed such that the flow of the cooling lubricant from the machine tool WZM to the tool WZG is not impaired.

[0209] In another variant shown in FIG. 13B, the sensor unit 16 (in which only its housing is shown for clarity) is at least approximately aligned with the axis of rotation 20 of the monitoring module 10, 26, 28, but the flow of the cooling lubricant is directed to the center of the monitoring module 10, 26, 28. For this purpose, both the sensor board 40 and the sensor unit 16 are provided with a central recess (shown here as a circular example). As can be seen in FIG. 13B, these central recesses overlap and the axis of rotation 20 of the monitoring module 10, 26, 28 passes through the center of the recess. During the operation of the monitoring module 10, 26, 28, the recess serves as a fluid channel FK, which therefore passes through the center of the monitoring module 10, 26, 28. This variant uses two uniaxial acceleration sensors, namely sensor X and sensor Y, arranged at 90° to each other and used in the sensor unit 16. Here, the sensor unit 16 can be provided with a central recess approximately aligned with the axis of rotation 20 and is provided with two acceleration sensors SX, SY. The first acceleration sensor SX is arranged in the yz plane and has a sensing axis perpendicular to the yz plane. The second acceleration sensor SY is arranged in the xz plane and has a sensing axis perpendicular to the xz plane. This allows concentricity monitoring even if the sensors X and Y are somewhat separated by a central flow path. Due to the spatial arrangement of sensor X in the YZ plane, no centrifugal acceleration occurs on the sensor during rotation in the absence of tilt. In the case of tilt in the X direction, an acceleration occurs in the tangential direction according to the speed and the concentricity error in the X direction. This applies analogously to the Y direction. As mentioned above, both accelerations are recorded proportionally by both sensors according to the amount and the direction (vector-wise). By analyzing the tangential acceleration, rotation does not affect the acceleration values.

[0210] During operation, the monitoring module 10, 26, 28 needs to be supplied with electrical energy. An energy supply unit V, as described with reference to FIG. 1, is provided in the monitoring module 10, 26, 28 for this purpose. This energy supply unit V comprises an energy storage unit, which in the simplest case consists of a replaceable or rechargeable battery or accumulator. With reference to FIGS. 14 and 15, the possibility of generating energy in the monitoring module 10, 26, 28 is now described. In these cases, the energy storage of the energy supply unit V can also comprise a battery or a capacitor with a relatively low capacity, which temporarily stores the generated energy. This requires, for example, a generator unit for converting the rotational energy into electrical energy. This electrical energy is fed to the energy storage unit via a rectifier circuit. The energy obtained from the energy storage unit can be brought to the nominal voltage required for the operation of the monitoring module 10, 26, 28 by an optional voltage regulator.

[0211] FIG. 14 shows the arrangement of the turbine unit TE in the fluid channels of the monitoring module 10, 26, 28 (shown in cross section). The turbine unit serves as a power generating unit that generates its own electricity. The flow of cooling (lubricating) medium is utilized by a turbine wheel 52. The turbine wheel 52, which has permanent magnets 54 (FIG. 14 shows two permanent magnets as an example), rotates by this flow of cooling (lubricating) medium. The turbine wheel 52 rotates relative to a circuit board 49 on which induction coils 56 (e.g. three coils arranged offset by 120° from each other, although in FIG. 14 only two of the coils 56 are referred to for clarity) are arranged and coupled to each other. The turbine wheel 52 and the circuit board 49 are arranged and aligned relative to each other such that the relative rotational movement between the turbine wheel 52 and the induction coils 56 induces a voltage in the induction coils 56, which is then stored in an energy storage device of the energy supply unit V.

[0212] Fig. 15 shows the arrangement of the flywheel drive of the monitoring module 10, 26, 28 (shown in cross section). The flywheel drive acts as a generating unit that generates its own power. The circuit board 51 acts as a stator, which is why it is directly coupled to the monitoring module 10, 26, 28. According to another example, alternatively, an indirect coupling between the circuit board 51 and the monitoring module 10, 26, 28 can be provided.

[0213] A coil cage 60 with an induction coil 62 is placed on the circuit board 51 as shown in Figure 15. To ensure stability at high processing speeds, the coil 62 is firmly glued to the coil cage 60 in a corresponding recess in the coil cage 60 (this also applies to the coil 56 described with reference to Figure 14). In this example, the coils 62 have manganese-zinc-ferrite cores and are connected to each other via the circuit board 51.

[0214] A flywheel 64 rotatably arranged in the monitoring module via several ball bearings 66 (only one reference 66 is shown in FIG. 15 for clarity) carries a permanent magnet 68 (only one reference 68 is shown in FIG. 15 for clarity). When the axis S and thus the monitoring module 10, 26, 28 is accelerated (positively or negatively), the mass inertia of the flywheel 64 creates a speed difference between the flywheel 62 and the plate 51. The flywheel 64 and the circuit board 51 are relatively arranged and aligned such that when the monitoring module 10, 26, 28 is accelerated between the flywheel 64 and the induction coil 68, this speed difference induces a voltage in the induction coil 68, which is then stored in the energy storage device of the energy supply unit V.

[0215] Now, with reference to figures 16 to 22, process sequences and partial process sequences that can be performed by the monitoring modules 10, 26, 28, the concentricity monitoring signal interface SGS and / or the machine tool WZM are described. In particular, process steps not mentioned in the previous description of the figures represent optional process steps for the concentricity monitoring and / or calibration execution. These optional process steps can be combined in particular with the process steps described with reference to figure 6 and with other process steps described in the context of the present disclosure (in particular with process steps related to the calibration execution).

[0216] FIG. 16 shows the sequence of the calibration process for one or more test speeds and the evaluation of concentricity in the concentricity monitoring module 10, 26, 28. According to FIG. 16, after the start of the calibration process in the monitoring, the monitoring module 10, 26, 28 sends a signal to the machine tool WZM module 10, 26, 28 and / or the concentricity monitoring signal interface SGS that it is ready to acquire the initial variables ax_initial, ay_initial. At this time, the monitoring module 10, 26, 28 is in the calibration mode. When the axis S rotates, for example, the machine tool WZM monitors whether the specified test speed is stable during the acquisition. The detection continues for a predetermined number of rotations of the axis S, in this example, 8 rotations. However, the present disclosure is not limited to this exact number of rotations in the detection period (including the evaluation time).

[0217] If the monitored test speed deviates significantly, e.g. by more than 10% from the specified test speed, no acceleration values ​​are recorded by the sensor unit 16. However, if the speed is stable, the acceleration values ​​ax_initial, ay_initial for the first (or only) test speed are recorded. In a next step, the initial values ​​ax_initial, ay_initial recorded by the sensor unit 16 are filtered. Furthermore, the exact test speed is determined during the acquisition using any of the variants described above. For this purpose, for example, another acceleration variable in the x-direction and / or y-direction can be determined by an additional sensor unit B, which can then be filtered in a similar way. Then, according to the example of FIG. 16, the average value of the variables ax_initial, ay_initial is determined from the number of rotations (i.e. the detection period).

[0218] The test speed can then be changed (e.g. increased). The optional nature of this step is indicated by the dashed outline of the "speed change" step in FIG. 16. The initial variables ax_initial, ay_initial are recorded again for the increased test speed as shown in FIG. 16. The acceleration variables ax_initial, ay_initial are recorded for all test speeds and the initial variables ax_initial, ay_initial (in particular their average values) are assigned to the correct test speed generally during the recording, thus determining a function of the test speed dependence of the initial variables ax_initial, ay_initial. This function is stored in the memory of the monitoring module 10, 26, 28 and is therefore available for calculating the total acceleration atot when the concentricity of the tool WZG is monitored by the monitoring module 10, 26, 28. To exit the calibration mode, the monitoring module 10, 26, 28 sends a signal to the machine tool WZM and / or the concentricity monitoring signal interface SGS that the calibration run is completed ("finished").

[0219] Figure 17 shows a partial sequence of the execution of a calibration for one or more test speeds and the evaluation of the initial variables ax_initial, ay_initial recorded in the calibration unit of the machine tool WZG (see Figure 4) or the concentricity monitoring signal interface SGS (see Figure 5). Some steps correspond to steps in Figure 16, so that instead of redundant explanations we refer to the respective steps in Figure 16, which steps also apply to the sequence of Figure 17.

[0220] According to FIG. 17, in particular the machine tool WZM or the concentricity monitoring signal interface SGS can trigger the execution of a calibration, i.e. start it, using one of the monitoring modules 10, 26, 28. After the "ready" message of the monitoring module 10, 26, 28, it sends the initial variables ax_initial, ay_initial recorded at a stable speed to the machine tool WZM / concentricity monitoring signal interface SGS. This continues until the recording period is reached. Then it stops sending the initial variables ax_initial, ay_initial and, in a calibration variant carried out at several test speeds, changes the speed. It records the initial variables ax_initial, ay_initial and again sends them at a stable speed until the recording period is reached. When this sequence has been carried out for all test speeds (this is the case when the machine tool WZM / concentricity monitoring signal interface SGS has received the initial acceleration variables ax_initial, ay_initial for all specified test speeds), the machine tool WZM / concentricity monitoring signal interface SGS ends the calibration process.

[0221] 18 shows a sequence of concentricity tests of a tool WZG performed at a single test speed in a monitoring module 10, 26, 28. The monitoring module 10, 26, 28 rotates together with the axis S of the machine tool WZM and the tool WZG, for example for machining a workpiece.

[0222] First, the monitoring module 10, 26, 28 is activated. This is done by a wake-up signal that switches the monitoring module 10, 26, 28 from energy saving mode (standby mode) to monitoring mode (measurement mode). In this example, the wake-up signal is sent to the monitoring module 10, 26, 28 from the machine tool WZM or from the concentricity monitoring signal interface SGS. However, the invention is not limited to this. In another variant, the wake-up signal is generated by another sensor unit B when another variable representing the acceleration in the x-direction and / or y-direction exceeds a wake-up threshold. The wake-up signal can also be generated when the amount of energy generated by the energy supply unit V exceeds a predefined level. In this case, the monitoring module 10, 26, 28 is set in the monitoring mode only when the monitoring module 10, 26, 28 is able to generate its own power. In addition to activating, the monitoring module 10, 26, 28 records potential impact events, such as a fall or a collision on the floor, and stores these in the memory of the monitoring module 10, 26, 28.

[0223] In the monitoring mode, the monitoring module 10, 26, 28 checks whether a speed is actually present in the monitoring module 10, 26, 28. If no speed is present, the monitoring module 10, 26, 28 returns to the energy saving mode. However, if a rotation speed is actually present in the monitoring module 10, 26, 28, the monitoring module remains in the monitoring mode and sends a signal to the machine tool WZM / concentricity monitoring signal interface SGS that it is ready for data acquisition (see also the description of FIG. 16). When the axis S rotates, the machine tool WZM monitors, for example, whether a specified test speed is stable during data acquisition. The detection continues for a given X number of rotations of the axis S (see FIG. 18), in this example for 8 rotations. However, the present disclosure is not limited to this exact number of rotations in the detection period.

[0224] In case of a significant deviation of the monitored test speed, for example, if the monitored test speed deviates from the specified test speed by more than 10%, the acceleration variables are not recorded by the sensor unit 16. However, if the speed is stable, the variables ax, ay representing the acceleration are recorded at the test speed. The acceleration variables ax, ay recorded by the sensor unit 16 are then filtered. Furthermore, before, after or during the detection and filtering (this also applies to all other embodiments of the present disclosure that include the corresponding steps), the initial variables ax_initial, ay_initial representing the acceleration are determined by reading the initial variables ax_initial, ay_initial detected in the calibration run according to FIG. 16. The total acceleration atot is determined and compared with the threshold value SW (see also FIG. 10). If the total acceleration atot is below the threshold value SW, a signal (OK) indicating that there is no runout error is sent to the machine tool WZM / runout monitoring signal interface SGS. On the other hand, if the total acceleration atot is equal to or greater than the threshold value SW, a signal (NOK) indicating that a runout error has occurred is sent to the machine tool WZM / runout monitoring signal interface SGS. The monitoring mode is then deactivated, so that the monitoring module 10, 26, 28 returns to the energy saving mode. Here, the deactivation is performed, for example, in response to a corresponding signal from the machine tool WZM / concentricity monitoring signal interface SGS. Alternatively, this deactivation can also be performed automatically by the module 10, 26, 28 in general (i.e. according to all the examples described herein) if no acceleration variables are determined for a predefined period of time (which indicates that the monitoring module 10, 26, 28 is not currently in use).

[0225] 19 shows a sequence of concentricity tests of a tool WZG performed at several test speeds in a monitoring module 10, 26, 28. The monitoring module 10, 26, 28 rotates together with the axis S of the machine tool WZM and the tool WZG, for example for machining a workpiece.

[0226] The sequence of Figure 19 differs from that of Figure 18 only in that the recording of the acceleration variables ax, ay, filtering thereof, recording of the initial variables ax_initial, ay_initial, determination of the total acceleration atot and comparison of said acceleration atot with the threshold value SW are performed for several test speeds, so that some steps correspond to steps in Figure 18, and so that here instead of redundant description we refer to the respective steps of Figure 18, which steps apply analogously in the context of the sequence of Figure 19.

[0227] In contrast to Fig. 18, according to Fig. 19, an accurate test speed n is determined for each run of detection (e.g. detection of acceleration variables) during detection of variables ax,ay representing acceleration using one of the variables mentioned above. The test speed is changed (e.g. increased) between the individual acquisition runs. After increasing the test speed, the steps of obtaining the acceleration variables ax,ay for the increased test speed, obtaining the accurate test speed, filtering the acceleration variables ax,ay, determining the initial acceleration variables ax_initial, ay_initial, determining the total acceleration atot and comparing it with the threshold value SW are performed again until the acceleration variables ax,ay have been obtained for all test speeds.

[0228] The test speed can be increased before sending a signal to the machine tool / concentricity monitoring signal interface SGS whether a concentricity error exists or not. In other words, a signal can be sent in a single data packet to the machine tool / concentricity monitoring signal interface SGS whether a concentricity error has occurred (NOK) or whether a concentricity error has not occurred (IO) at any test speed. Alternatively, these results can be sent separately to the machine tool / concentricity monitoring signal interface SGS for each test speed.

[0229] Figure 20 shows a sequence of concentricity tests of a machine tool WZM (see Figure 4) or a tool WZG performed at a single test speed and at different test speeds at a concentricity monitoring signal interface SGS (see Figure 5), where one of the monitoring modules 10, 26, 28 rotates together with the axis S of the machine tool WZM and the tool WZG, for example for machining a workpiece.

[0230] After starting the concentricity check by the machine tool WZM / concentricity monitoring signal interface SGS, the system waits for the monitoring module 10, 26, 28 to send a signal that it is ready to perform an acceleration measurement. Then, (for example as described with reference to FIG. 19), an acquisition of the variables ax, ay representing the acceleration is performed (not shown in FIG. 20). These acceleration variables ax, ay are received by the machine tool WZM / concentricity monitoring signal interface SGS either continuously (as shown in FIG. 20) or when the acquisition in the monitoring module 10, 26, 28 is completed, and are stored in the memory of the machine tool WZM / concentricity monitoring signal interface SGS. As soon as all recorded acceleration variables ax, ay and the associated test velocities are received, an evaluation is started in the machine tool WZM / SGS concentricity monitoring signal interface. The test velocities (one or more) are determined during the acquisition and the variables ax, ay representing the acceleration are filtered. Furthermore, initial variables ax_initial, ay_initial, which represent the accelerations (for several test speeds as a test speed dependent function), are determined, for example by reading them out from a memory of the machine tool / concentricity monitoring signal interface SGS. A total acceleration atot is determined for each test speed and compared with a threshold SW depending on the test speed. If this evaluation is performed at the concentricity monitoring signal interface SGS, the concentricity monitoring signal interface SGS can send a signal to the machine tool WZM that a concentricity error of the m tool WZG exists (NOK) or not (IO). However, this optional step, shown in a dashed box in FIG. 20, is not necessary if the evaluation is performed at the machine tool WZM. The concentricity characteristics of the tool WZG at the corresponding test speed are known to the machine tool WZM / concentricity monitoring signal interface SGS, which completes the concentricity test at the machine tool WZM / concentricity monitoring signal interface SGS.

[0231] Fig. 21 shows a partial sequence of a concentricity check of a tool WZG, which is performed on a machine tool WZG (see Fig. 4) or on a concentricity monitoring signal interface SGS (see Fig. 5). One of the monitoring modules 10, 26, 28 rotates together with the axis S of the machine tool WZM and the tool WZG, for example, for machining a workpiece. For the activation and deactivation of the monitoring modules 10, 26, 28, the transmission of the "ready" status to the machine tool / concentricity monitoring signal interface (abbreviated as WZM / SGS in Fig. 21) and the stability of the rotational speed during the detection period, see for example the corresponding explanations in Fig. 18, which are also valid here.

[0232] The sequence of Fig. 21 is a variant in which the measurement variables are continuously transmitted to the machine tool WZM / concentricity monitoring signal interface SGS. The transmitted measurement variables can be analyzed, for example, according to the sequence of Fig. 20 (not shown in Fig. 21).

[0233] During the monitoring of whether the speed is stable or not, the sensor unit 16 of one of the monitoring modules 10, 26, 28 records the variables ax,ay representing the acceleration and transmits them continuously to the machine tool WZM / concentricity monitoring signal interface SGS. According to Fig. 21, this can be done immediately after the recording of the individual acceleration variables ax,ay. Optionally (as indicated by the dashed outline of the step in Fig. 21 of checking whether the module memory is full or not), the acceleration variables ax,ay can also be stored in the memory of the monitoring module 10, 26, 28 at least until it is almost full or until a defined amount of data is reached. Alternatively, a defined data packet containing several acceleration variables ax,ay can be temporarily stored in the module memory for a certain period of time and transmitted to the machine tool WZM / concentricity monitoring signal interface SGS after the expiration of this period. When the recording period is reached, the transmission of the recorded acceleration variables ax,ay is terminated. Since in this variant the acceleration variables ax,ay are continuously monitored, the acquisition period can last for example for the entire machining cycle of the workpiece or at least part of it, especially if this (partial) machining cycle is performed with the same monitoring module 10, 26, 28 and the same tool WZG. Alternatively, the detection period can be adapted to the duration of one or more machining steps (drilling, milling, etc.) performed by the tool WZG. The module memory can be set in particular so that it can keep all values ​​recorded during a recording period, if the recording period is known. As this variant according to FIG. 21 requires a high energy input, the monitoring module 10, 26, 28 can be equipped with a power generation unit for generating its own energy, especially as explained with reference to FIG. 14 or 15.

[0234] 22 shows a partial sequence of a concentricity test (evaluation) of a tool WZG, which is performed at one of the monitoring modules 10, 26, 28 or at the concentricity monitoring signal interface SGS from the point of view of the machine tool WZM, which rotates together with the axis S of the machine tool WZM and the tool WZG, for example for machining a workpiece.

[0235] First, the machine tool WZM inserts the monitoring module 10, 26, 28 into the axis S of the machine tool WZM and rotates the axis S at the required acquisition speed (see also the explanation of steps (i) and (ii) in FIG. 6). Then, the monitoring module 10, 26, 28 waits until it receives a signal that it is ready to acquire data. For a detailed explanation of this step, reference is made, for example, to the corresponding explanation in FIG. 18, which is equally valid here. Once the monitoring module 10, 26, 28 is ready, it records the variables ax, ay representing the accelerations. The evaluation can be performed in the monitoring module 10, 26, 28 as shown in FIGS. 18 and 19, or in the concentricity monitoring signal interface SGS as shown in FIG. 20 (not shown in FIG. 22).

[0236] The machine tool WZM waits until information about the concentricity error of the tool WZG is available. This information is transmitted to the machine tool WZM by the evaluation unit, i.e. by the monitoring module 10, 26, 28 or the run-out monitoring signal interface SGS. If a concentricity error is present in the tool WZG (NOK), the machine tool WZM removes the monitoring module 10, 26, 28 from the shaft S and cleans it by blowing it out with a compressed air stream (these steps are omitted in FIG. 22). The machine tool WZM then exchanges the monitoring module 10, 26, 28 on the shaft and then waits again (this step is also omitted in FIG. 22) until information about the concentricity error of the tool is available (it carries out a concentricity test again according to one of the described variants). If a concentricity error is still present, the machine tool WZM first blocks the machining of the workpiece, for example to prevent further production of dimensionally inaccurate (reject) workpieces. Furthermore, the rotation of the axis S is stopped in order to put the machine tool WZM and the monitoring module 10, 26, 28 to which the tool WZG is attached into a safe state. Furthermore, the error is displayed on the display of the machine tool WZM and / or an acoustic error signal is emitted. These three steps can basically be performed simultaneously. If there is no concentricity error (NOK), the machine tool WZM releases the machining of the workpiece.

[0237] Of course, one of the (partial) methods for calibration and / or concentricity checking etc. described in connection with the present disclosure can then be carried out again using the monitoring module 10, 26, 28 with the attached tool WZG. The machine tool WZM and / or the concentricity monitoring signal interface are possibly influenced by the described computer program product.

[0238] It is understood that the exemplary embodiments and variants described above are not exhaustive and do not limit the subject matter disclosed herein. In particular, it will be apparent to those skilled in the art that features of the various embodiments and variants can be combined with one another and / or various features of the embodiments and variants can be omitted without departing from the subject matter disclosed herein.

Claims

1. A concentricity monitoring module (10) for a tool (WZG) that rotates during operation, comprising: a tool interface (12) configured to receive the tool (WZG) in rotation; a tool mounting interface (14) configured for insertion into a tool holder (WZGA) of a machine tool (WZM) or a machining center (BA); a sensor unit (16) assigned to the concentricity monitoring module (10) so as to be passed through by the axis of rotation (20) of the concentricity monitoring module (10) and configured to detect variables (ax, ay) in a plane (E) oriented essentially perpendicular to the axis of rotation (20) of the concentricity monitoring module (10) when the concentricity monitoring module (10) rotates together with the rotating tool (WZG) and / or tool holder (WZGA); A computing device (22), receiving a value (ax, ay) representing the acceleration recorded by said sensor unit (16); determining a total acceleration (atot) based on the recorded values ​​(ax, ay) representing the acceleration; During the detection of the quantities (ax, ay) representing the acceleration, the total acceleration (atot) is compared with a threshold (SW) depending on the rotation speed of the runout monitoring module (10); a computing device (22) configured to determine that a concentricity error of the rotating tool (WZG), the concentricity monitoring module (10) and / or the tool holder (WZGA) exists if the total acceleration (atot) is greater than the threshold value (SW); a communication device (24) communicatively connected to the computing device (22) and configured to transmit to the machine tool (WZM) / machine-achieving tool (BA) a signal indicating whether or not there is a concentricity error in the rotating tool (WZG), the concentricity monitoring module (10) and / or the tool holder (WZGA); A concentricity monitoring module (10) comprising:

2. A tool holder module (26) for monitoring the concentricity of a tool (WZG) that rotates during operation, comprising: a tool interface (12) configured to receive the tool (WZG) in rotation; a tool holder (WZGA) configured to be inserted into a shaft (S) of a machine tool (WZM) or a machining center (BA); a sensor unit (16) associated with the concentricity monitoring tool holder module (26) such that a rotation axis (20) of the concentricity monitoring tool holder module (26) extends therethrough, and configured to detect, via the concentricity monitoring tool holder module (26), variables (ax, ay) in a plane (E) oriented substantially perpendicular to the concentric rotation axis (20) when the concentricity monitoring tool holder module (26) rotates together with the rotating tool (WZG) and / or the shaft (S); A computing device (22), receiving a value (ax, ay) representing the acceleration detected by the sensor unit (16); determining a total acceleration (atot) based on the recorded values ​​(ax, ay) representing the acceleration; During the acquisition of the quantities (ax, ay) representative of the acceleration, the total acceleration (atot) is compared with a threshold value (SW) that depends on the rotational speed of the concentricity monitoring tool holder module (26), a computing device (22) configured to determine that a concentricity error of the rotating tool (WZG) and / or the tool holder (WZGA) exists if the total acceleration (atot) is greater than the threshold value (SW); a communication device (24) communicatively connected to the computing device (22) and configured to transmit a signal indicating whether or not there is a concentricity error in the tool (WZG) and / or the tool holder (WZGA) to the machine tool (WZM) / the machining center (BA); A concentricity monitoring tool holder module (26) comprising:

3. A concentricity monitoring tool module (28), comprising: a tool (WZG) that rotates during operation; a tool holder (WZGA) configured to be inserted into a shaft (S) of a machine tool (WZM) or a machining center (BA); a sensor unit (16) assigned to the concentricity monitoring tool module (28) so as to extend along its axis of rotation (20), and assigned to detect variables (ax, ay) in a plane (E) oriented substantially perpendicular to the axis of rotation (20) of the concentricity monitoring tool module (28) when the concentricity monitoring tool module (28) rotates with the axis (S); A computing device (22), receiving a value (ax, ay) representing the acceleration detected by the sensor unit (16); determining a total acceleration (atot) based on the recorded values ​​(ax, ay) representing the acceleration; During the detection of the quantities (ax, ay) representative of the acceleration, the total acceleration (atot) is compared with a threshold value (SW) that depends on the rotational speed of the concentricity monitoring tool module (28), a computing device (22) configured to determine that a concentricity error of the concentricity monitoring tool module (28) exists when the total acceleration (atot) is greater than the threshold (SW); a communication device (24) communicatively connected to the computing device (22) and configured to transmit a signal indicating whether or not there is a concentricity error of the concentricity monitoring tool module (28) to the machine tool (WZM / the machining center (BA); A concentricity monitoring tool module (28) comprising:

4. A machine tool (WZM) or a machining center (BA), an axis (S) that rotates about a rotation axis (D) during operation of the machine tool (WZM / machine-achieving tool (BA)) and is configured to receive and operatively communicate with a tool mounting interface (14) of the concentricity monitoring module (10) of claim 1; a communication device (30) arranged to receive signals from the communication device (24) of the concentricity monitoring module (10) of claim 1; A control device (22) connected to a communication device (24) of the machine tool (WZM) / the combined machine tool (BA), receiving values ​​(ax, ay) representative of accelerations detected by a sensor unit (16) of a concentricity monitoring module (10) according to claim 1; determining a total acceleration (atot) based on the recorded values ​​(ax, ay) representing the acceleration; During the detection of the quantity (ax, ay) representing the acceleration, the total acceleration (atot) is compared with a threshold (SW) depending on the rotation speed of the axis (S); a control device (22) configured to determine that a runout error of the concentricity monitoring module (10) of claim 1 exists if the total acceleration (atot) is greater than the threshold value (SW); A machine tool (WZM) or a machining center (BA) comprising:

5. A concentricity monitoring signaling interface (SGS), comprising: a communication device (36) configured to receive signals from the concentricity monitoring module (10) of claim 1 and to transmit signals to the machine tool (WZM) / machine-machine combination (BA); a computing device (38) connected to the communication device (36) of the concentricity monitoring signaling interface (SGS), receiving values ​​(ax, ay) representative of accelerations detected by a sensor unit (16) of a concentricity monitoring module (10) according to claim 1; determining a total acceleration (atot) based on the recorded values ​​(ax, ay) representing the acceleration; During the detection of the quantities (ax, ay) representative of the acceleration, the total acceleration (atot) is compared with a threshold value (SW) that depends on the rotational speed of the axis (S), the rotational speed of the concentricity monitoring module (10), the rotational speed of the concentricity monitoring tool holder module (26) or the rotational speed of the concentricity monitoring tool module (28), a computing device (22) configured to determine that a runout error of the concentricity monitoring module (10) of claim 1 exists if the total acceleration (atot) is greater than the threshold value (SW); Equipped with The communication device (36) of the concentricity monitoring signal transmission interface (SGS) is configured to transmit a signal to the machine tool (WZM / machine-achieving machine (BA)) indicating whether or not there is a runout error of the tool (WZG), the concentricity monitoring module (10), the concentricity monitoring tool holder module (26) and / or the concentricity monitoring tool module (28) rotating during operation.

6. 1. A method for monitoring the concentricity of a tool (WZG) rotating on a machine tool (WZM) or machining center (BA) during operation, comprising: (i) automatic insertion of a monitoring module (10; 26; 28) that rotates during operation or a monitoring module (10; 26) that rotates during operation and a rotating tool (WZG) into an axis (S) of a machine tool (WZM) / machine-machine (BA), the rotating monitoring module (10; 26; 28) having a sensor unit (16) assigned to the monitoring module (10; 26; 28) that rotates so that a rotation axis (20) of the rotating monitoring module (10; 26; 28) passes through it; (ii) rotating the axis (S) of the machine tool (WZM) / machine complex (BA) at a specified speed; (iii) receiving and / or detecting quantities (ax, ay) representative of acceleration in a plane (E) oriented substantially perpendicular to the axis of rotation (20) of the rotating monitoring module (10, 26, 28) while the rotating monitoring module (10, 26, 28) rotates at a predetermined speed; (iv) determining a total acceleration (atot) based on the recorded quantities (ax, ay) representing said acceleration; (v) comparing said total acceleration (atot) with a threshold value depending on the rotational speed of said monitoring module (10; 26; 28) during the detection of said quantities (ax, ay) representative of said acceleration; (vi) determining that there is a concentricity error of the rotating monitoring module (10; 26; 28) and / or the rotating tool (WZG) if the total acceleration (atot) is greater than a threshold value (SW); A concentricity monitoring method comprising:

7. A computer program product comprising instructions for carrying out the method of claim 6.

8. and / or a further sensor unit (B) spaced apart radially from the axis of rotation (20) and arranged to detect another variable (ax, ay) representative of an acceleration in a plane (E) oriented substantially perpendicular to the axis of rotation (20) substantially simultaneously with the detection of the variable (ax, ay) representative of the velocity, wherein the computing device (22) is further arranged to receive another quantity representative of the acceleration detected by the further sensor unit (B) and to determine from the another quantity representative of the acceleration a rotational speed of the concentricity monitoring module (10) / the concentricity monitoring tool holder module (26) / the concentricity monitoring tool module (28) during the detection of the quantity (ax, ay) representative of the acceleration; 2. The concentricity monitoring module (10) according to claim 1, wherein the concentricity monitoring module (10) comprises two opposing acceleration sensors (B1, B2) arranged in a plane (E) radially spaced from and oriented substantially perpendicular to the axis of rotation, the acceleration sensors (B1, B2) having measurement axes lying in a straight line or in a plane perpendicular to the plane (E) and containing the axis of rotation (20), the acceleration sensors (B1, B2) supplying measurements from which an average of a further quantity representative of the acceleration is formed, or the communication device (24) is configured to transmit a further variable representative of the acceleration to the machine tool (WZM) / machine-machine (BA) and / or to the concentricity monitoring signal transmission interface (SGS).

9. 2. The concentricity monitoring module (10) of claim 1, wherein the computing device (22) is configured such that the rotational speed of the concentricity monitoring module (10) / concentricity monitoring tool holder module (26) / concentricity monitoring tool module (28) during detection of the quantity representative of acceleration is based on a frequency that prevails during detection of the quantity (ax, ay) when the rotation axis (20) of the concentricity monitoring module (10) / concentricity monitoring tool of the concentricity monitoring tool holder module (26) / concentricity monitoring tool module (28) is oriented essentially horizontally or during detection of the quantity (ax, ay) representative of acceleration.

10. A concentricity monitoring module (10) as claimed in claim 1, comprising a photosensitive unit (PE) having a photosensitive surface (50) arranged on the concentricity monitoring module (10) / concentricity monitoring tool holder module (26) / concentricity monitoring tool module (28), wherein the photosensitive unit (PE) is configured to detect a difference in brightness during detection of variables (ax, ay) representing the acceleration, and the arithmetic unit (22) is configured to determine the rotational speed of the concentricity monitoring module (10) / concentricity monitoring tool holder module (26) / concentricity monitoring tool module (28) based on the frequency of the brightness difference immediately before, immediately after and / or during detection of the variables (ax, ay).

11. 2. The concentricity monitoring module (10) of claim 1, wherein at least the sensor unit (16) and another sensor unit (B) are arranged on a sensor circuit board (40), the sensor circuit board (40) is connected to a circuit board holder, and the position of the circuit board holder (42) can be adjusted perpendicular to the rotation axis (20) via adjustment means (44) of the concentricity monitoring module (10) / concentricity monitoring tool receiving module (26) / concentricity monitoring tool module (28).

12. 2. The concentricity monitoring module (10) of claim 1, wherein the sensor unit (16) comprises a central recess oriented substantially coaxially with the rotation axis (20) and two acceleration sensors (B1, B2), a first acceleration sensor arranged in a y-z plane and having a sensing axis perpendicular to the y-z plane, and a second acceleration sensor arranged in an x-z ​​plane and having a sensing axis perpendicular to the x-z plane.

13. A concentricity monitoring module (10) as described in claim 1, further comprising an energy supply unit (V) arranged to switch from an energy saving mode or a standby mode to a monitoring mode in response to a wake-up signal, and / or to switch the sensor unit (16), another sensor unit (B), the computing device (22) and / or the communication device (24) from an energy saving mode or a standby mode to a monitoring mode in response to a wake-up signal.

14. 14. The concentricity monitoring module (10) according to claim 13, wherein the wake-up signal is or is triggered by a signal generated by a further sensor unit (B) as soon as another variable representative of the acceleration exceeds a wake-up threshold or received via a communication device (24) from the machine tool (WZM) / machine-machine (BA) and / or a monitoring signal transmission interface (SGS) or generated when the amount of energy generated by the energy supply unit (V) exceeds a predetermined level.

15. 15. The concentricity monitoring module (10) according to claim 13 or 14, wherein the energy supply unit (V) comprises an energy storage unit for storing energy or a power generation unit for generating electrical energy.

16. 16. The concentricity monitoring module (10) of claim 15, wherein the power generating unit comprises a stator (60) that is or can be directly or indirectly coupled to a tool holder (WZGA) of the concentricity monitoring tool holder module (26) / concentricity monitoring tool module (28), and wherein the power generating unit further comprises a rotor (64) associated with the concentricity monitoring module (10) / the concentricity monitoring tool holder module (26) / the concentricity monitoring tool module (28) in cooperation with the stator (60) so as to generate electrical energy during rotational acceleration of the concentricity monitoring module (10) about the axis of rotation (20), during rotation of the concentricity monitoring tool holder module (26) / the concentricity monitoring tool module (28).

17. The sensor unit (16) is configured to operate independently of normal operation, and the concentricity monitoring module (10) / concentricity monitoring tool holder module (26) / 2. The concentricity monitoring module (10) of claim 1, wherein the concentricity monitoring tool module (28) rotates with the axis (S) at a substantially constant rotational speed or at several different substantially constant rotational speeds to detect initial values ​​(ax_initial, ay_initial) representative of accelerations in a plane (E) oriented substantially perpendicular to the rotation axis, and wherein the computing device (22) is instructed to store the initial variables (ax_initial, ay_initial) representative of accelerations together with the corresponding rotational speeds (S) in a memory of the concentricity monitoring module (10) / the concentricity monitoring tool holder module (26) / the concentricity monitoring tool module (28) and / or the communication device (24) is configured to transmit the variables (ax_initial, ay_initial) representative of accelerations together with the corresponding rotational speeds to a machine tool (WZM) / machine machining center (BA) and / or a concentricity monitoring signal interface (SGS).

18. 2. The concentricity monitoring module according to claim 1, wherein the computing device is further arranged to process variables (ax, ay) and / or initial variables (ax_initial, ay_initial) representative of accelerations detected by another sensor unit (16) and / or another variable representative of accelerations and / or rotational speeds of the concentricity monitoring module (10) / concentricity monitoring tool holder module (26) / concentricity monitoring tool module (28) detected by another sensor unit (B) while detecting the variables (ax, ay) representative of accelerations in a specific time window between 50 milliseconds and 200 milliseconds in the form of data packets, the processing being performed by operations such as signal filtering, averaging and / or determining a frequency spectrum for each time window, and to transmit the processed data packets to a machine tool (WZM) / machine-machine (BA) and / or a concentricity monitoring signal interface (SGS).

19. A concentricity monitoring module (10) as described in claim 1, wherein the computing device (22) is further configured to monitor at least one other process parameter when the concentricity monitoring module (10) rotates with the rotating tool (WZG) and / or tool holder (WZGA) or when the concentricity monitoring tool holder module (26) rotates with the rotating tool (WZG) and / or shaft (S) or when the concentricity monitoring tool module (28) rotates with the shaft (S), the at least one process parameter comprising vibration, temperature, coolant pressure, coolant flow rate, cutting force and / or torque.

20. 20. The concentricity monitoring module (10) of claim 19, wherein the computing unit (22) is configured to determine a total acceleration (atot) based on subtraction of variables (ax_initial, ay_initial) representing an initial acceleration from corresponding variables (ax, ay) representing an acceleration representation.

21. 2. The concentricity monitoring module (10) of claim 1, wherein the computing device (22) is configured to determine an amount and / or a direction of a runout error when a runout error exists, and the communication device (24) is configured to transmit the amount and / or the direction of the runout error to a machine tool (WZM) / machine-achieving tool (BA) or a concentricity monitoring signal interface (SGS), and / or the communication device (24) is configured to transmit a signal of the presence of a concentricity error to the machine tool (WZM) / machine-achieving tool (BA) or the concentricity monitoring signal interface (SGS) when a concentricity error exists while the concentricity monitoring module (10) / concentricity monitoring tool module (26) / concentricity monitoring tool module (28) is rotating with the axis (S).

22. 2. The concentricity monitoring module (10) of claim 1, configured to: detect variables (ax, ay) representing accelerations; detect another variable representing accelerations; determine a total acceleration (atot); determine whether a concentricity error exists; and send a signal indicating whether a concentricity error exists; wherein the concentricity monitoring module (10) / concentricity monitoring tool module (26) / concentricity monitoring tool module (28) together with the axis (S) is moved by a machine tool (WZM / machine-achieving machine tool (BA)) from an axis start position to a machining position on a workpiece, the time being less than 5 seconds.

23. 2. The concentricity monitoring module of claim 1, wherein the concentricity monitoring module is adapted to recognize functions executed by the concentricity monitoring module or initiated in other modules or assemblies by means of a predefined speed profile, the predefined speed profile comprising at least: (i) speed; (ii) predefined speed durations (sequences); (iii) speed change gradients; (iv) predefined speed durations (sequences); and (v) predefined speed durations (sequences); (iii) speed change gradients from one speed stage to the next; and / or (iv) speed durations from one speed stage to the next of an axis of a machine tool detected via generator voltage evaluation; and may comprise a function "perform a teach-in or pairing process", a function "perform a calibration process", a function "wake-up or generate a wake-up signal", a function "enter a monitoring or measurement mode", and / or a function "enter a deep sleep or standby mode".

24. 2. The concentricity monitoring module (10) according to claim 1, adapted to perform the following: detecting a quantity (ax, ay) representative of the acceleration, which starts only when a defined rotational speed is reached; detecting another variable representative of the acceleration; determining the total acceleration (atot); determining whether a concentricity error exists; and transmitting a signal indicating whether the concentricity error exists, wherein during the evaluation time, the rotational speed of the shaft is essentially constant or varies within a range of up to 10% of the rotational speed.

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