Method for checking the clamping state during the acceleration phase

Abstract

A method for checking the clamping state of a tool receiver or a tool clamped in a tool clamping device of a rotor unit (3) of a motor-driven machine tool unit (1) is proposed, wherein a spacing (u) of a measuring sensor head (5) from a component of the rotor unit (3) being measured is measured, at least one time- and / or position-dependent sequence (20, 21) of the spacing values measured by the sensor head (5) is recorded, wherein, in order to improve the integration of the method, the recording of the first and second time- and / or position-dependent sequences is carried out during the acceleration of the rotor unit (3) relative to the stator unit (2), in particular when the rotor unit is started, wherein the time- and / or position-dependent information of the sequence vectors of the first and / or second sequences is scaled using the respective associated current speed (v0).

Description

Technical Field

[0001] The present invention relates to a method for checking the clamping state of a tool receiver or clamping tool, wherein the tool is clamped in a tool clamping device of a rotor unit according to the present invention. Technical Background

[0002] According to existing technology, for example from EP 3 581 328 A1, a method for checking the clamping state in a machine tool unit is known, wherein the interval relative to the rotor unit is measured via a sensor head arranged in a fixed position. In this case, for example, before processing a workpiece during a specific time period, a time series of the measured values ​​is recorded and evaluated so that its axial runout error can be determined. Furthermore, other devices for checking the accuracy of the working spindle in a machine tool are known, for example from EP 2 312 270 A1, which has a length measuring system with a glass rod carrying a marking and reading device, or a device for identifying foreign objects in the gap between the tool and the spindle, as described in DE 102006 0919 A1. Summary of the Invention

[0003] One object of the present invention is to provide a method for checking the clamping state, which can be integrated into the processing technology in a simpler way.

[0004] The objective is achieved through the characteristic features described in this invention, based on the methods of the type mentioned in the introduction.

[0005] Advantageous embodiments and developments of the invention are possible. The method for checking the clamping state according to the invention is characterized in that, in principle, there is no further time loss during actual measurement, and measurements can be performed in an unlimited manner, for example, even after each tool change or tool receiver change. In this way, it can also be integrated into the process in a simpler way, especially since it is not necessary to provide a separate time period during which the inspection method can or must be performed.

[0006] According to the present invention, a motor-driven machine tool unit is first considered, comprising a stator unit and a rotor unit, wherein the rotor unit is rotatably supported about a rotation axis. The rotor unit, rotating relative to the stator unit, is typically driven by a motor spindle. The actual machining tool (milling tool, drill bit, etc.) is held or clamped in a tool receiver arranged in a tool clamping device, which is intended to be considered part of the spindle head of the rotor unit. The tool clamping device therefore has a holding device for the tool receiver. The tool clamping device acts with a clamping force and is displaced in the longitudinal direction of the rotation axis. In this case, for example, a part of the clamping device can be pulled into a tapered receiving member, so that the tool receiver or tool can then be clamped by a radial force. By releasing the clamping force, the clamped tool is released again and can be removed or replaced from the machine tool.

[0007] Furthermore, an inspection device is provided for checking the clamping state of a tool or tool receiver, the device having one or more sensor heads for sensor detection. Typically, a single sensor head is sufficient. An actual sensor is mounted in the sensor head, measuring its distance relative to the rotor unit, wherein the sensor itself is correspondingly arranged in the stator unit. The sensor data is processed or evaluated using a computer-controlled electronic unit or electronic evaluation system.

[0008] In principle, at least one sensor head is mounted on the stator unit at a fixed position in the area of ​​the tool clamping device, enabling it to measure both the end face and the lateral direction on the rotating spindle head. During the clamping of the tool or tool receiver, deformation caused by stuck debris, tilted positioning of the tool, tool receiver, etc., mainly occurs in the area of ​​the tool interface or on the tool receiver.

[0009] However, in principle, the sensor head can also be arranged to vary in position. Typically, for example, debris may become trapped in the tool holder and fall between the tool and the tool holder or jaws, causing the tool to not be directly positioned within the tool holder, or the tool holder to become easily (and elastically) deformable, maintaining constant concentricity, constant axial runout of the tool / tool ​​holder, or no longer guaranteeing operation without angular changes. A breach in concentricity usually indicates specific damage to the process. This deformation typically occurs both laterally and at the end face, and in principle, can also be detected at this location. At the end face, the interval parallel to the axis of rotation is measured, as is the interval extending laterally relative to the axis of rotation. All deformation caused by the displacement of the rotor unit can be determined in this way.

[0010] In principle, measurements can be taken at a 90° angle relative to the surface and / or axis of rotation of the rotor unit, but measurements can also be taken at different angles.

[0011] Especially for machine tools, there are particularly high requirements for machining accuracy. During machining operations, the tool must be inserted into the tool receiver or tool holder and moved in a precisely defined manner so that the workpiece to be processed is handled within the expected tolerance limits. Even when the machine tool and, in particular, the tool holder are manufactured to the required accuracy, additional factors are involved when using the machine to prevent the defined concentricity / axial runout from continuing or to prevent angular errors from occurring. During machine operation, chips generated during the processing operation can remain stuck in the tool holder, held in the tool receiver, or in the tool, ensuring that when changing tools, the new tool is not clamped in the actual desired position. The same applies to changing the tool receiver. During clamping, pressure occurs instead at localized locations, such as between the tool and the tool receiver or between the tool receiver and the tool holder. It is also conceivable that the tool receiver can retract into the tool holder in such a way that the retracted position has changed in the direction of the rotation axis relative to the earlier installation configuration.

[0012] Because the debris is sometimes very small, these errors are often difficult to determine, and they also occur randomly after the machining process when the tool receiver or other areas of the machine tool are cleaned in a routine manner. However, such concentricity errors or incorrect angular positions of the tool can cause the workpiece to exceed tolerance limits after the processing operation.

[0013] The sensor head measures interval values ​​in a time- or position-dependent sequence. If the sensor head records a time series of interval values, it is usually also a position-dependent sequence because the rotor unit rotates in a time sequence, unless a rotation is always precisely completed between the recordings of each measurement value or multiple integer rotations have been performed.

[0014] Generally, according to the present invention, not only can the variation in axial runout be determined, but also, for example, the variation in angular position and concentricity.

[0015] The method according to the invention is characterized in that at least one mark at another location on the rotor unit or rotor shaft is predetermined. This allows the reference mark to be used even in the case of unknown speed or angular velocity, and enables clear detection of when the rotor unit has precisely performed one rotation. This is particularly advantageous when determining axial runout or angular error, without considering other sensors and without the participation of a separate rotary encoder in the evaluation. The mark can preferably also be detected simultaneously by the sensor head or sensor head during the actual measurement operation. Therefore, in principle, no additional sensor is required. However, it is also conceivable to provide additional sensors to identify the mark separately, especially when the interval measurement is intended to be independent of mark identification.

[0016] In a variation of the invention, particularly on the measuring ring, there is an option to arrange more than one mark. In this way, even more information can be obtained through measurement, such as enabling the detection of rotation direction, signal orientation, or synchronization. To obtain additional information when a mark is detected, the mark can, for example, also have different shapes, such as an angled trapezoid, so that, for example, the rotation direction can be identified from the shape.

[0017] Since the current speed of the rotor unit can also be detected by the markings, the accuracy of the error measurement according to the method of the invention is also substantially affected by this. Although previously the measurement needed to be performed at a constant speed in order to compare and correlate the measured values ​​with each other, the present invention is based on saving this originally required time period and, for example, enabling meaningful measurements to be performed during the acceleration phase of the rotor unit, especially when the machine tool's rotor unit is started.

[0018] When the machine starts, the rotor unit accelerates relative to the stator unit. During this time period, the method according to the invention is immediately applied. In this case, the interval values ​​of the first or second sequence are typically recorded outside the marked area. Since these measurements are performed during the acceleration phase of the rotor unit's rotation, however, these interval values ​​cannot initially be easily correlated because the time scan is typically performed at a predetermined timing rate, that is, within equal time periods, the accelerated rotor unit rotates to different degrees between two consecutive times, and therefore, the positions, especially those with at least two measurement sequences, no longer correspond.

[0019] The path / time relationship or angle / time relationship is described as follows:

[0020] s(t) = 0.5at 2 +v0t,

[0021] Where s(t) is the time-dependent path traveled in time period t or the angular range traveled in time period t, a is the acceleration, and v0 refers to the current velocity at the beginning of time period t.

[0022] According to the invention, a sequence of measured values ​​is recorded. In this case, the interval between the sensor head fixed to the rotor unit and the stator unit is determined, and it is measured whether this interval changes during the rotation of the rotor unit. In order to be able to compare the sequences with each other or evaluate the data (e.g., to be able to subtract the sequences), the interval values ​​must be able to be correlated with the corresponding positions. However, time is typically measured during the recording of the interval values.

[0023] When the machine starts, the rotor unit is initially accelerated. This acceleration can occur in a substantially uniform manner, that is, 'a' is essentially constant. However, in principle, there is no constant acceleration phase when the rotor unit starts.

[0024] However, at the start of the startup process, acceleration is typically not constant over a specific period of time. The speed as a function of time curves slightly to the left in this range, known as the S-curve, meaning the rotor unit starts up slightly slower, allowing for a smoother startup. This is also referred to as the "acceleration limit." Therefore, it is advantageous not to measure from a stationary state, but rather within a range close to constant acceleration.

[0025] For each sequence, a certain number of sequence vectors can be formed accordingly, containing:

[0026] The measured interval values,

[0027] Time information when measuring interval values, and

[0028] The speed value, the so-called current speed, will typically correspond to at least two sequence vectors if the rotor unit is accelerated and if speed measurements are performed within a specific time period.

[0029] According to the present invention, the mathematical scaling is performed under the following conditions: the two measurements are performed successively in a short period of time, so the angular part caused by the acceleration expressed by the quadratic component of the equation of motion can be ignored.

[0030] This linearization is possible only if the time interval between the measurements of two interval values ​​is chosen to be sufficiently short. Therefore, even if one of the measurements is performed later and the actual speed value differs from the associated current value, the current speed is still associated with both the first and second sequences. Since time is quadratic and describes a decrease in acceleration, linear scaling of speed is possible under the given mathematical conditions. For example, measurements can also be performed during the machine's startup phase. The time interval during which the machine needs to start (whether short or long) must always be waited for, because the precise conditions for processing operations (e.g., tool speed) are typically not yet met within that time. However, it is particularly advantageous if, when the rotor unit has already started, the presence of, for example, axial runout error, concentricity error, or angular error can be determined, because where applicable, the process can be interrupted, and tool cleaning or repositioning can be performed before processing operations. For example, in the case of tool replacement, changes in axial runout, concentricity, or angular position should generally be considered. If this deviation is so large that it exceeds a threshold (as previously defined in the applicable context), an error exists.

[0031] As a result of the method according to the invention, production time can also be increased, which is directly related to cost advantages. In a particularly advantageous manner, the rotor unit accelerates uniformly throughout the recording of the measurements. This further simplifies the evaluation, where the approximation simply involves omitting the acceleration portion from the path or angle / time diagram. This is possible because the sequentially measured values ​​are recorded one after another in very short intervals, and therefore their time intervals or angular intervals are very small, meaning the acceleration term is related to the square of time, and thus the uniform acceleration is negligible.

[0032] Therefore, in embodiments of the invention, scaling is performed by considering the acceleration at different times through the current velocity and the time interval between determining the velocity measurement. Due to the omission of the acceleration term, the path / time graph or angle / time graph contains a linear term that depends linearly on time, and the velocity (path velocity or angular velocity) is introduced as a constant rather than an acceleration. According to embodiments of the invention, the current velocity can be determined in different ways. For example, it may be advantageous to determine the current velocity by referring to the time between consecutive detections of a marker measured by the sensor head. Such a measurement is more accurate when the marker constitutes only a relatively narrow portion of the angular segment, ideally constituting a local marker. Furthermore, it is conceivable that the marker can be constructed such that it occupies a predetermined arc portion, and the time it takes for the marker extending over a previously known angular portion to pass through the sensor head is determined.

[0033] For example, if a single marker is provided, meaning that the marker passes precisely through the sensor head each time it rotates, then a current velocity is measured once, which is somewhat imprecisely determined by the velocity variation within a rotation. Differences in acceleration as a result of that time interval of rotation are then disregarded. Conversely, when the marker constitutes only a small fraction of the entire 360-degree rotation angle, the measurement is correspondingly more precise, for example, determined when the front of the marker in the direction of rotation reaches the region of the sensor head and the rear of the marker in the direction of rotation subsequently passes through the sensor head.

[0034] For example, the markings of a construction variant of the invention can be constructed as grooves, such as in a measuring ring, which is separately assembled to the rotor unit, such that the regions outside and inside the groove have different spacing values. The lateral surfaces, for example, formed at the edges of the groove, are then measured, and the spacing values ​​measured by the sensor head are changed accordingly. The groove can, in principle, have lateral surfaces extending vertically or radially in the direction toward the rotation axis, or inclined lateral surfaces.

[0035] Therefore, during the measurement of the interval value, the sensor head can follow the path. Depending on the current angular velocity or path velocity, the generation of lateral forces can be observed over shorter or longer time periods. In particular, in the case of a high-rotational configuration, a linearized approximation can be performed in such a way that, for example, measurements of the first or second time- and / or position-related sequences of the measured values ​​are performed within the rotation of the rotor unit. In this case, it is assumed that the velocity remains constant within the rotation. Precisely, in a high-rotational configuration, as occurs in a machine tool, this approximation naturally tends to have relatively small errors. Especially at the end of the start-up phase, higher angular velocities can be expected, making the estimated measurements performed within this range more accurate than those at the beginning of the start-up phase.

[0036] When a side of a marker is detected at the edge of a marker covering a specific angle, the marker is partially divided into partial markers so that the marker can be identified using the sensor head, for example, when the marker reaches and then leaves the sensor head's area. For instance, when the marker reaches the sensor head's area and the sensor head detects the first side, the marker can be measured. In this case, the time interval between the two measurement events of the marker has the same value in each case. Similarly, when the marker moves out of the sensor head's area again, a time point can be used. In this way, error estimation can be performed because for each measurement point—that is, for two points with the same interval value—the current velocity can be determined, but the time interval between these two points can also be measured simultaneously.

[0037] As explained above, the corresponding velocity can be determined by referring to a mark extended within a specific angular range or by referring to the appearance of the same mark after rotation. In this way, how the velocity changes over time can be estimated so that, if it is assumed that the acceleration term at the time series points can be neglected, the error occurring during the approximation period can be estimated from it.

[0038] In this way, it is also advantageous to determine how precisely the method operates, and the method can be adjusted accordingly where appropriate. In an advantageous embodiment of the invention, a time- or position-related sequence of interval values ​​can be used as a reference measurement. For example, it is conceivable to measure a new machine tool, a new tool receiver, or a new tool where debris cannot be recorded by the processing operation, and to record a first sequence of measurements as a reference. It is also conceivable to allow the rotor unit to run with the cleaned tool receiver after the cleaning operation to generate corresponding reference measurements. Thus, any deviation from the reference measurement can be determined, and then assessed whether the deviation is large enough to indicate a concentricity error, altered axial runout, or angular error. In this way, the accuracy of the processing can be significantly improved. The measurement of the operating conditions constitutes a comparative measurement, related to the reference measurement.

[0039] Using a sequence of interval values, markers can be specifically set as initial points, particularly during subtraction and / or Fourier transform, to enable the interval values ​​to be correlated with each other. In this respect, reference measurements are advantageous because, as a result of the measurement itself, it can be determined when a complete rotation has been performed. This is particularly advantageous when the method is performed without any value related to the current speed or velocity provided to the electronic evaluation system by other sensors or machine control, but rather with only the value of the sensor head or sensor tip.

[0040] In principle, the interval profile can be completely recorded for a single rotation. However, very high rotation numbers and measurements at relatively high scan rates are generally advantageous. For example, axial runout or angular errors exist as a result of debris or as a result of a tool / tool ​​receiver that has been mounted / clamped at an angle, where, for example, the tool is positioned at an angle relative to the axis of rotation, periodically occurring deviations can be identified. To be able to evaluate this, it is therefore advantageous to perform a Fourier transform of the signal, particularly as a Discrete Fourier Transform (FFT) or DFT, to simplify the evaluation. For this purpose, the values ​​of the first and second sequences can be subtracted from each other, where the positions of the interval measurements must correspond. However, this subtraction can also be performed after the Fourier transforms of the corresponding sequences. Ideally, all interval values ​​would be identical, such that there is no change in axial runout compared to a reference measurement, no compromise in concentricity, and no change in angular position. However, due to static and systematic errors, it is simply not possible to expect, during measurement, that even without a change in axial runout, the sensor head would not change in angular position, or that there would be no concentricity error, and that the same interval values ​​would always be measured accurately.

[0041] If the interval values ​​are irregular, they can be determined accordingly at specific singularities because they are detected periodically, and therefore can also be associated with frequencies that can be determined as a result of a Fourier transform. It is also conceivable that a subsequent subtraction can be performed between the averages of a time- or location-related sequence.

[0042] Depending on the type of error present (axial runout error with localized deformation or angular error with uniformly spaced variations), this can also lead to the identification of patterns. Once the identification pattern is known, it provides information about the type of error involved, such as whether debris is stuck, where the debris can be found, or whether the tool or tool receiver is tilted. For this purpose, artificial intelligence (especially machine learning) methods can be used to identify and evaluate the type of error, whether it is axial runout or angular error. The use of neural networks is also possible in this regard. This measurement advantageously enables not only the identification of the error's occurrence but also the determination of what the error actually involves in more detail, ultimately enabling the implementation of solutions, such as by selecting a cleaning machine method. This can significantly reduce machine downtime. For clamped debris, deformation of the tool receiver components or tool clamping device components at different locations can be specifically anticipated. In the evaluation sequence, changes in the measurement signal, i.e., changes in time or position-related intervals, can therefore be searched.

[0043] However, it should be considered that each measurement is also, in principle, subject to error. The more precise the measurement, the higher the scan rate used for the measurement, and the greater the likelihood that the same interval value will not always be measured in a single rotation, even with sufficient axial runout. Therefore, it is advantageous to be able to estimate the tolerance. In particular, a threshold can be determined from which it is practically assumed that debris has become stuck or that another error has caused axial runout or concentricity deviation or angular error, which must actually be corrected. At this point, it is advantageous to compare such changes in the measurement relative to a predetermined threshold.

[0044] In embodiments of the invention, during the evaluation sequence, particularly in the Fourier transform at the frequency value corresponding to revolutions per unit time of the rotor unit, the difference in intervals is compared with a threshold. If the threshold is exceeded, axial runout error / concentricity error / angular error is assumed, because, for example, debris held in the clamping device or between the tool receiver and the tool has caused localized deformation.

[0045] Furthermore, in a variant of the invention, the displacement of the rotor unit or axis of rotation can be determined based on the difference between two in a time or positional sequence. This displacement can, for example, have the effect of the tool being placed on the workpiece earlier or later than considered or provided by machine control. Therefore, even when the tool or tool receiver is not tilted, machining accuracy can be affected accordingly. This variation can occur when the tool / tool ​​receiver is, for example, also engaged without any angular error. Utilizing such a deviation, the tool may protrude further beyond the tool receiver, or the tool receiver may protrude further beyond the clamping device, or the tool receiver may be further positioned internally.

[0046] Furthermore, the corresponding method can also be used in principle in the stopped state when comparing the corresponding displacements (e.g., before and after the tool or the tool receiver changes). Attached Figure Description

[0047] Figure 1 This is a schematic diagram of a machine tool unit according to the present invention;

[0048] Figure 2 : is a schematic diagram of an extract of an inspection method for checking the clamping state according to the present invention;

[0049] Figure 3 : This is a diagram illustrating the deformation pattern as an evaluation result;

[0050] Figure 4 This is a graph showing the relationship between speed and time, used to illustrate the startup of the rotor unit;

[0051] Figure 5 : This shows the radially oriented groove that is fitted onto the measuring ring;

[0052] Figure 6 The diagram shows the interval / time graph during the detection of the groove, and

[0053] Figure 7 : This is a diagram illustrating the error estimate of the reference interval / time plot. Detailed Implementation

[0054] Embodiments of the invention are illustrated in the accompanying drawings, and are explained in more detail below with reference to other details and advantages.

[0055] In detail, as shown in the attached diagram:

[0056] Figure 1 This is a schematic diagram of machine tool unit 1, which has stator unit 2 and rotor unit 3. Figure 1 Specifically, the spindle head can be considered as part of the rotor unit 3. The stator unit 2 has a sensor ring 4, in which the sensor head is mounted in the form of an axial sensor 5. The rotor unit 3 includes a measuring ring 6, which is made of metal and produced of a paramagnetic material, which is advantageous in this case. The axial sensor 5 is arranged to measure the distance between itself and the end face surface of the rotor unit 3. However, radial measurement relative to the axis of rotation is also conceivable. The surface defining the distance is located on the measuring ring 6. The axial sensor 5 is constructed as an eddy current sensor so that the most accurate measurement can be obtained regardless of any contamination.

[0057] The sensor head / axial sensor 5 is connected to the electronic unit 7, and together they form an inspection device 8, which is in turn connected to the machine control unit 9, so that, where applicable, intervention can be performed in control in the event of excessively strong axial runout error.

[0058] In a particularly preferred development, only one sensor head 5 is provided. For example, it is conceivable to use a separate trigger sensor to identify an optical reference mark on the measurement ring 6, wherein such a trigger sensor can also be mounted on the sensor ring 4, for example. The mark can also be constructed as a groove, etc. Using this trigger sensor, only the initial point of measurement is triggered, allowing for a simpler determination of the phase relationship between the measured values ​​during evaluation. The trigger sensor is not absolutely necessary and is not included in... Figure 1 It is shown in more detail below.

[0059] The stator unit 2 includes a cover 10 for the sensor ring 4 and an additional bearing cover 11. The tool clamping device 12 is assembled to the rotor unit 3 (in...). Figure 1 (A conical ring is shown in the image).

[0060] When the tool is held in the tool receiver, a series of 20 reference measurements are initially recorded with the new machine unit 1 in each case. This can be performed in the factory or at the customer's location. Reference measurements can also be performed with the tool or tool receiver, but this is not absolutely necessary; however, it increases measurement accuracy in some cases and, where applicable, also helps identify small debris in the area of ​​the tool interface, especially when it is desirable to use a separate tool or tool receiver. During operation, using the same tool / tool ​​receiver, a new sequence 21 of interval values ​​is subsequently determined. A set of reference measurements can be performed for different tools or tool receivers, and this measurement increases the accuracy of identification. Since sequences 20, 21 are recorded when machine unit 1 starts up and therefore during the acceleration of rotor unit 3, the position indications of the corresponding interval values ​​must be scaled so that they can be compared with each other. Figure 2 Accordingly, the values ​​for sequences 20 and 21 have been scaled. Figure 2 In the process, difference 21 is formed. Subsequently, frequency analysis 23 of the signal is performed in the form of Fourier transform. Check (method step 24) for deviations at specific frequencies, such as the rotation frequency of rotor unit 3 or the frequency at which such changes occur. If these exceed a threshold, there is a disturbance variable, such as deformation caused by blockage debris in the interface region (amplitude evaluation: method step 25).

[0061] exist Figure 3The diagram illustrates typical deformation patterns, where in Figure A, there are no debris and the amplitude distribution is significantly more uniform across the entire angular range, while in Figure B, debris is trapped in the tool receiving member, resulting in distortion with a significant change in amplitude (between 10-11 o'clock and 4-5 o'clock). Therefore, a threshold can also be determined. In Figure C, the debris is located at a different angular position, causing Figure C to differ from Figure B. It's mainly about phase.

[0062] During cascaded operations, clamping status checks can be performed in a very short portion of the startup phase. For example, in Figure 4 In the first 300ms, the rotor unit accelerates, during which measurement detection is performed. The rotor unit speed is shown according to the time path t, and the S-curve S shows a curve slightly curved to the left, indicating a slow start-up to prevent uneven movement. Linearization is disadvantageous in this region because the acceleration is not constant, and approximations by ignoring the acceleration portion are generally too inaccurate. However, there is essentially a constant acceleration, meaning the speed is linearly related over time t. If axial runout cannot be established, processing can be performed. Otherwise, braking must be performed for safety reasons according to the invention. After approximately 300ms, a constant speed of approximately 4000 rpm is reached for the exemplary processing operation.

[0063] exist Figure 5 The diagram shows a cross-section through rotor unit 3, which has a measuring ring with grooves in the side regions. An enlarged view shows edge regions F1 and F2, which can be configured as side surfaces and detected at correspondingly high scan rates. Therefore, for example, when the sensor head detects the corresponding side surfaces at the beginning and end of groove N, the current speed can also be determined, since the angular region extending from groove N is known, and the angular interval between these two side surfaces is also known, making it possible to determine only the time interval between the appearances of the side surfaces.

[0064] Figure 6 Two illustrations are depicted, showing the path of the measurement interval u between the sensor head and the rotor unit as the groove N passes through the sensor head at different speeds in each case (in this case, 10 times the speed at a time). In the regions of sides F1 and F2, the time dependence of the interval u is sloping because the groove N in regions F1 and F2 also has a sloping path. Therefore, this path is compressed in time at the relatively high speed of 10v0.

[0065] Figure 7 This again demonstrates how short time intervals can be used to estimate the error in linearization (acceleration term omitted).

[0066] The same groove N is measured one after another in time relative to its interval u. Due to the uniform acceleration, subsequent measurements of the groove, for example, occurring at velocity v1, are compressed relative to the previous one (i.e., v1 > v0). Rotation exists between two measurement events. In linearization, it is assumed that the same velocity will exist between two measurement events. The time interval between two measurement events is the time between two points on the same side F1 (or F2, independently), with the same spacing. Therefore, the maximum error can be estimated:

[0067] Δv / Δt=(v1-v0) / Δt.

[0068] List of reference numerals in the attached diagram:

[0069] 1-Machine Tool Unit

[0070] 2-Stator Unit

[0071] 3-Rotor Unit

[0072] 4-Sensor Ring

[0073] 5-Axial Sensor

[0074] 6-Measuring ring

[0075] 7-Electron Unit

[0076] 8-Inspection device

[0077] 9-Machine Control Department

[0078] 10-Covered area

[0079] 11-Bearing cover

[0080] 12-Conical ring / tool ​​clamping device

[0081] 20-Reference Signal

[0082] 21-Measurement Signal

[0083] 22-Differential Operator

[0084] 23-Frequency Analysis

[0085] 24-Frequency Search

[0086] 25-Amplitude Assessment

[0087] A-Deformation Mode (No Debris)

[0088] B and C - Deformation modes (with debris in different locations)

[0089] F1, F2 - Side surfaces at the edges of the grooves

[0090] N-groove

[0091] u-interval

[0092] t - time v0 - velocity -Phase difference a-Acceleration

Claims

1. A method for checking the clamping state of a tool receiver and / or a tool, wherein the tool receiver and / or tool is clamped in a tool clamping device (12) of a rotor unit (3) of a motor-driven machine tool unit (1), wherein the tool receiver and / or tool is releasably fixed and clamped by means of the tool clamping device (12), the tool clamping device being capable of being acted with a clamping force, wherein the tool clamping device is displaced in the longitudinal direction of a rotation axis when the tool is clamped, wherein the tool clamping device is arranged in the spindle head of the rotor unit (3), wherein the machine tool unit has a stator unit (2), and the rotor unit is rotatably arranged about a rotation axis relative to the stator unit, wherein, The method includes the following steps: Provide at least one sensor head (5) for determining the interval value (u), The sensor head (5) is positioned at the stator unit (2); The interval value (u) from a portion of the rotor unit (3) to the sensor head (5) is measured. Record at least one time- and / or location-related sequence of interval values ​​measured by the sensor head (5). To determine axial runout and / or concentricity deviation and / or angular variation, only consider the time and / or position-related sequence of the measured interval values ​​(u) relative to the portion of the spindle head rotating relative to the sensor head. Its features are: A mark (N) is set on the rotor unit (3), wherein the sensor head (5) detects the mark (N) on the rotor unit during measurement. The current speed (v0, v1) of the rotor unit (3) is detected by referring to the marker (N) on the sensor head. During the rotational acceleration of the rotor unit (3) relative to the stator unit (2), first and second time- and / or position-related sequences of the interval values ​​(u) measured by the recording sensor head are executed. The corresponding current velocity is associated with an interval value (u) of the first and second time- / or location-related sequences, so as to form a sequence vector from the interval value, the time- / or location-related information and the current velocity (v0); The time and / or position-related information of the sequence vectors of the first and / or second time and / or position-related sequences is scaled using the corresponding associated current velocity (v0) so that the sequence vectors of the first and / or second time and / or position-related sequences each have at least one interval value at their corresponding positions on the rotor unit (3). When axial runout deviation is detected, the rotor unit is braked.

2. The inspection method according to claim 1, characterized in that, During the acceleration of the rotation of the rotor unit (3) outside the mark (N), first and second time- and / or position-related sequences of the interval value (u) measured by the sensor head (5) are executed.

3. The inspection method according to claim 1, characterized in that, The rotor unit (3) accelerates in a uniform manner throughout the recording.

4. The inspection method according to claim 1, characterized in that, The scaling is performed by taking into account the acceleration (a) of the time between the current velocity (v0) determined at different times and the determined velocity measurement.

5. The inspection method according to claim 1, characterized in that, The current speed (v0) of the rotor unit (3) is determined by reference marker (N): Mark (N), which marks a specific angular portion of the rotor unit (3) during rotation, and the time required for the sensor head (5) to pass through the determined sensor head (5) at the known angular portion, and / or The time between two sequence detections of marker (N) is measured by sensor head (5).

6. The inspection method according to claim 1, characterized in that, The groove is used as a marker (N) such that the areas outside and inside the groove have different spacing values ​​(u).

7. The inspection method according to claim 1, characterized in that, Recording the first and / or second time- and / or position-related sequences is performed during the rotation of the rotor unit (3).

8. The inspection method according to claim 1, characterized in that, The time and / or location-related sequences of the interval values ​​(u) used as reference measurements are recorded by the clamped tool and / or tool receiver.

9. The inspection method according to claim 1, characterized in that, The time and / or position-related sequence of the interval value (u) is recorded by the clamped tool and / or tool receiver when the rotor unit (3) starts up and reaches the operating condition.

10. The inspection method according to claim 1, characterized in that, The marker (N) is used as an initial point, and the initial point being evaluated is associated with the sequence of the interval values ​​so that the interval values ​​of different sequences can be correlated with each other.

11. The inspection method according to claim 1, characterized in that, Determine the evaluation sequence of values ​​using at least one of the following calculations: The difference between the two time series is calculated (22), followed by a Fourier transform of the difference between the first and second time- and / or location-related series (23), and / or Perform a Fourier transform on each sequence, and then find the differences between the corresponding Fourier-transformed time series, and / or... Calculate the average of time- and / or location-related sequences, and then find the differences between the averages.

12. The inspection method according to claim 11, characterized in that, Check the deviation of the evaluation sequence (24, 25), if the deviation of the evaluation sequence exceeds a predetermined threshold, and if the deviation exceeds the predetermined threshold, assume that there is a change in axial runout and / or a change in concentricity and / or a change in angle.

13. The inspection method according to claim 11, characterized in that, In the evaluation sequence, the difference between the interval values ​​is compared with a threshold, and if the threshold is exceeded, it is assumed that there is a change in axial runout and / or a change in concentricity and / or a change in angle.

14. The inspection method according to claim 1, characterized in that, The displacement of the rotor unit and / or the rotating shaft is determined based on the difference between two of the time and / or position-related sequences.

15. The inspection method according to claim 1, characterized in that, Artificial intelligence is used to determine whether there are changes in axial runout and / or concentricity and / or angle.

16. The inspection method according to claim 1, characterized in that, During the rotational acceleration of the rotor unit (3) relative to the stator unit (2), when the rotor unit is started, the first and second time- and / or position-related sequences of the interval values ​​(u) measured by the sensor head are executed.

17. The inspection method according to claim 8, characterized in that, Before the first processing operation performed by the machine tool unit (1) and / or after the cleaning operation, the time and / or position-related sequence of the interval value (u) used as a reference measurement is recorded by the clamped tool and / or tool receiver.

18. The inspection method according to claim 8, characterized in that, For each tool and / or tool receiver used, a time and / or position-related sequence of the interval value (u) used as a reference measurement is recorded by the clamped tool and / or tool receiver.

19. The inspection method according to claim 9, characterized in that, When the rotor unit (3) starts up and reaches the following operating condition, a time and / or position-related sequence of interval values ​​(u) is recorded by the clamped tool and / or tool receiver: the operating condition is later than the reference measurement and is used as a comparison measurement for the reference measurement.

20. The inspection method according to claim 10, characterized in that, The marker (N) is used as an initial point, and the initial point being evaluated is associated with the sequence of the interval values ​​so that the interval values ​​of different sequences can be correlated with each other during the difference (22) and / or Fourier transform (23).

21. The inspection method according to claim 11, characterized in that, The Fourier transform (23) is the discrete Fourier transform.

22. The inspection method according to claim 13, characterized in that, In the evaluation sequence, the difference between the interval values ​​is compared with a threshold in the Fourier transform at the frequency value corresponding to the revolutions per time unit of the rotor unit.

23. The inspection method according to claim 15, characterized in that, The axial runout variation is the axial runout error.

24. The inspection method according to claim 15, characterized in that, The concentricity change is the concentricity error.

25. The inspection method according to claim 15, characterized in that, The change in angle is angular error.

26. The inspection method according to claim 15, characterized in that, Conclusions about errors and / or variations are drawn from the results of machine learning as sequences.

Images