Device with a drive unit and method

Abstract

A device is proposed comprising a drive unit for driving a movable drive part and a switchable friction brake, wherein the drive part can be braked and / or held stationary, wherein the device includes sensor means and a control device, wherein the control device processes a detectable sensor measurement value of a measurement parameter, and wherein, when the friction brake is in braking action and starting from the static state of the drive part, an increase in the drive dimension of the drive unit against the effect of the friction brake in braking action occurs until the drive part passes from the static state into a temporally subordinate slip state in which a braking torque caused by the friction brake is maintained on the driven movement of the drive part.According to the invention, the control device and the sensor means are designed such that, over a predetermined measuring interval, which lies within a range in which the drive part is in a slipping state, several sensor measurements can be recorded for a predetermined measuring parameter, each at a time offset, wherein the measuring parameter correlates with a braking torque during the slipping state in order to determine a braking effect of the friction brake on the drive part in an actual state of the friction brake on the basis of the several sensor measurements of the same measuring parameter.

Description

State of the art

[0001] In devices such as machines, for example, machine tools, a drive unit is used to drive a movable drive part of the device or machine. For example, the movable drive part can be linearly or rotationally driven, for example, continuously driven. Drive motors, for example, are frequently used as the drive.

[0002] To ensure safe operation of the device, different types and design principles of braking devices are used in practice to decelerate the moving drive part or the units driven by it. For example, switchable friction brakes are used to decelerate the driven, moving drive part through friction between friction partners, which are at least partially part of the friction brake. The friction brake can be designed to hold the drive part stationary in a static state.

[0003] In order to avoid a malfunction or failure of the friction brake or to minimize the potential danger to persons in the immediate vicinity of the device, high and defined safety requirements are placed on the operator of the device, machine or machine tool. Object and advantages of the invention

[0004] The object of the present invention is to improve a device described above with regard to safe operation. In particular, compliance with specifications or defined standards regarding the functional testing of brakes such as friction brakes is to be improved.

[0005] This problem is solved by the independent claims. The dependent claims demonstrate advantageous and useful further developments.

[0006] The invention is based on a device with a drive unit for driving a movable drive part of the device and with a switchable friction brake, wherein the moving drive part can be braked by the friction brake through friction between friction partners and / or can be held stationary in a static state of the drive part, wherein the device comprises sensor means and a control device for operating the device, wherein the control device processes a sensor measured value of a measurement parameter that can be detected by the sensor means, and wherein, when the friction brake is in braking action and starting from the static state of the drive part, an increase in the drive dimension of the drive unit takes place against the effect of the friction brake in braking action,until, due to the effective drive dimension, the drive part moves from the static state into a slipping state of the moving drive part which is temporally subordinate to the static state, whereby in the slipping state of the drive part a braking torque caused by the friction brake is maintained on the driven movement of the drive part.

[0007] The essence of the invention is that the control device and the sensor means are designed such that, over a predetermined measuring interval which lies within a range in which the drive part is in the slipping state, a plurality of sensor measured values ​​can be recorded with a time offset for a predetermined measuring parameter, wherein the measuring parameter correlates with a braking torque of the friction brake acting on the driven drive part during the slipping state in the measuring interval in order to determine a braking effect of the friction brake on the drive part in an actual state of the friction brake on the basis of the plurality of sensor measured values ​​of the same measuring parameter.

[0008] For example, the current braking function or the actual condition of the friction brake with regard to braking effect can be effectively and safely assessed. For example, a reliable brake test is guaranteed by the Technical Committee "Machine Tools" and the Technical Committee "Machine Tools Safety" in compliance with EN ISO 16092-2:2020.

[0009] For example, the friction brake is subjected to a dynamic braking torque measurement. The brake test is performed by comparing a cyclically measured actual value with a previously measured actual value. For example, the previously measured actual value correlates with the new state of the friction brake. For example, the previously measured actual value is used as the target value.

[0010] For example, the friction brake is deliberately caused to slip during a brake test. This involves increasing the drive power of the drive unit to the driven drive component from a stationary state, where the friction brake is engaged or applied. After overcoming a static holding torque acting on the drive component when the friction brake is engaged, a measurement is taken to record a dynamic braking torque. For example, the friction brake remains engaged during this time.

[0011] For example, parameters that can be specified during the measurement, such as operating parameters of the device, or drive unit parameters such as motor parameters of an electric drive forming the drive unit, are used to measure the actual state of the friction brake. For example, the motor parameters "actual current" in amperes (A) and / or the torque constant Kt in newton meters per ampere (Nm / A) are recorded or measured and further processed. For example, the motor torque correlates with the braking torque of the friction brake.

[0012] For example, the friction brake comprises a spring arrangement, for example a mechanical spring arrangement with a mechanical spring. For example, the friction brake comprises a spring arrangement for providing a braking effect and / or for providing a braking force.

[0013] For example, the friction brake is spring-assisted, while the friction brake is spring-actuated. For example, the switchable friction brake is actuated or activated by a mechanical spring. For example, the effect of the friction brake can be switched on and off by the mechanical spring.

[0014] For example, the friction brake comprises two adjacent, e.g., opposite, friction partners that are movable relative to each other. For example, one friction partner is assigned to the friction brake, and another friction partner is assigned to an element to be driven, e.g., the drive part.

[0015] For example, a measurement interval lies within a time range in which the drive component is in a slipping state. For example, all measurements for recording the sensor values ​​fall within the slipping state. For example, the end of the slipping state can be detected and / or mathematically determined when a measured limit value, e.g., a measured limit value of the braking torque, is reached.

[0016] For example, the measurement interval is defined by a measurement distance traveled by the drive part in the slipping state. For example, the measurement distance refers to a path, such as a movement distance, traveled by the drive part in the slipping state. For example, with respect to the drive part, the measurement distance can be measured as the distance traveled by a part of the device that is motion-coupled to the drive part during the measurement time.

[0017] For example, the measuring travel is the travel of the moving drive part in the slipping state, e.g., a linear travel traveled by the linearly moving drive part or a part coupled to it. For example, the measuring travel is in the millimeter range or in the range of a fraction of a millimeter.

[0018] For example, the friction brake of the device refers to any one of all possible types of friction brakes.

[0019] For example, the friction brake of the device is a spring-actuated brake or a spring-actuated friction brake. Such a friction brake is described, for example, in the EN ISO 16092-2:2020 standard. This standard is directed, for example, at safety brakes.

[0020] For example, the friction brake goes into an unactuated or non-braking state when energy is applied, e.g., by applying a magnetic force or electrical energy. For example, when the brake is switched off or the power fails, as with a safety brake, the friction brake returns to a spring-actuated state. For example, the friction brake is a rest brake that exerts a braking effect without the application of energy, solely through spring force.

[0021] For example, the friction brake is an energy-operated brake that goes into the actuated state or into the braking state by supplying energy, e.g. by supplying a magnetic force or electrical energy.

[0022] For example, the friction brake returns to the deactivated state when the power is switched off or in the event of a power failure. For example, such a friction brake, such as a working brake, only brakes when energy is supplied, e.g., only when electrical energy is supplied, or only when a magnetic force is applied, e.g., the electromagnetic force of an electromagnet.

[0023] For example, if the drive part is rotatably movable, e.g., rotates under power or performs a rotary motion, the measurement path is a path along a circular path or a rotational path in a slip state, e.g., determinable by an angular value. For example, the measurement path is a path of a rotary motion of the drive part or of a part of the device that is motion-coupled to the drive part, or of another component outside the device that is motion-coupled to the drive part and rotates or moves linearly or along a motion curve.

[0024] For example, the measuring range is a fraction of a complete rotation of 360 degrees, for example, in the range of a few degrees. For example, the measuring range lies between zero and 360 degrees within exactly one rotation of the drive part. For example, the acquisition of multiple sensor measured values ​​occurs within a rotation of the drive part by 360 degrees, or within exactly one complete rotation of the drive part.

[0025] For example, the measuring interval is defined by a measuring time that lies within a period in which the drive component is in the slipping state. For example, the measuring time lies in the range of seconds, for example, in the range of one second or in the range of two seconds. For example, the measuring time lies in the range of a fraction of a second, for example, in the range of tenths of a millimeter or in the range of a few hundredths of a second, or for example, the measuring time lies in the range of milliseconds. For example, the measuring time lies in the range of seconds, for example, in the range of one second or in the range of up to two seconds.

[0026] For example, a start measurement time of the measurement interval and / or an end measurement time of the measurement interval can be defined. For example, multiple start measurement times and corresponding end measurement times can be specified for a measured value, for example, for several or all of the multiple recorded measured values.

[0027] For example, the control device and the sensor means are configured to determine a starting time of the slipping state of the drive part, wherein the braking effect of the friction brake is determined only after the starting time of the slipping state of the drive part and after the expiration of a first temporal phase of the slipping state of the drive part following the starting time. For example, the slipping state is divided into several temporal phases, comprising at least a first temporal phase and a final temporal phase.

[0028] For example, the starting time of the first measurement interval occurs after the end of the first temporal phase of the slipping state or after a start-up phase. During the start-up phase, for example, a non-representative, for example, abruptly changing or discontinuous friction behavior of the friction partners is expressed.

[0029] For example, the impact of initial slipping behavior of the drive component from a stationary state, e.g., a startup behavior of the drive component during the startup phase, on the recording of the sensor measured values ​​is excluded. The startup phase regularly distorts a measurement result or is generally not representative for the evaluation of the braking effect of the friction brake. As a rule, slipping behavior of the drive component from a stationary state during an initial phase of the slipping state is not meaningful for assessing the actual state of the braking effect of the friction brake. For example, a distortion of the assessment of the braking effect of the friction brake is avoided.

[0030] After the end of the starting behavior or after the end of the first phase of the slipping state, the friction brake or the drive part behaves evenly and not abruptly or discontinuously.

[0031] For example, in a temporal phase of the slipping state of the drive part following the first temporal phase of the slipping state, for example in several of the subsequent temporal phases of the slipping state, sensor measured values ​​are recorded, such as the determination of the gradient of the braking torque or a parameter that correlates with the braking torque.

[0032] For example, recorded sensor measurements for the respective different temporal phases of the slipping state of the drive component are only considered for the measurement at a time offset from the start of the slipping state. The time offset from the start of the slipping state to the beginning of the measurement of a first sensor measurement value, or the length of the first temporal phase of the slipping state or the start-up phase, is, for example, a few milliseconds, a few hundredths of a second, or a few tenths of a second.

[0033] For example, the change in the braking torque of the friction brake or a correlated parameter is evaluated over time.

[0034] For example, to determine the end of the start-up phase or the first phase of the slipping condition, a limit value analysis is performed for recording a sensor measurement. For example, starting at the beginning of the slipping condition, a gradient in the braking torque curve or a correlated parameter is recorded, approaching zero. Once the gradient reaches zero or the gradient in the braking torque curve approaches zero, the recording of sensor measurement values ​​or a first sensor measurement value begins, followed by the recording of further sensor measurement values.

[0035] For example, the sensor measurements are recorded as soon as the gradient of the braking torque curve falls below a predefined threshold or when the braking torque curve reaches a zero gradient. This is when the measurement interval for recording the sensor measurements begins.

[0036] For example, by not taking into account or by hiding or excluding the starting behavior of the friction brake, a falsification of the measurements and thus a falsification of the evaluation of the braking effect of the friction brake is avoided or minimized.

[0037] For example, by masking out the starting behavior of the friction brake, a starting peak of the slipping state, e.g. with a short-term higher detectable braking torque, is not taken into account and therefore does not have a distorting effect on the measurement.

[0038] For example, the slipping state is divided into several temporal phases, e.g., a plurality of three or more than three temporal phases, for example, 4 to 20 or more than 20 temporal phases. For example, all temporal phases of the slipping state have the same duration, or the multiple temporal phases all have different durations, or the multiple temporal phases have two or more phases with the same duration and two or more phases with the same duration.

[0039] For example, the slipping state of the drive part is followed by a free, practically almost frictionless movement of the friction partners between the friction surfaces of the friction partners and thus of the drive part, which moves freely driven.

[0040] For example, the control device and the sensor means are designed in such a way that the number of the multiple sensor measured values ​​offset in time can be specified.

[0041] For example, the number of time-shifted multiple sensor measured values ​​is two or more than two time-shifted sensor measured values ​​are recorded in the measuring interval.

[0042] For example, the number of sensor readings in a corresponding measuring interval is ≥ 2, ≥ 10, ≥ 20, ≥ 30, ≥ 40, ≥ 50, ≥ 60, ≥ 70, ≥ 80, ≥ 90 or ≥ 100 sensor readings.

[0043] For example, exactly 100 sensor readings, or exactly 120 readings, or ≤ 500 sensor readings are recorded in a measurement interval. For example, the multiple sensor readings are recorded at the same time interval, e.g., with a time interval between the sensor readings of 20 milliseconds or 20 mS, of 40 mS, or of more than 40 mS.

[0044] For example, that the measuring interval lies within a range within which the rotating drive part completes one revolution.

[0045] For example, the measurement interval corresponds to a rotation time of the drive part, within which the drive part completes one or exactly one revolution, or exactly 360 angular degrees. For example, the measurement interval corresponds to a rotation time of the drive part, within which the drive part travels a distance that is smaller than the distance the drive part travels during one rotation of 360 angular degrees around its axis of rotation, or smaller, for example, 300 angular degrees, or smaller, for example, 200 angular degrees, or smaller, for example, 180 angular degrees.

[0046] For example, the control device and the sensor means are designed in such a way that when the friction brake is actuated before the measuring interval, the friction brake is in a predeterminable conditioning state. For example, the actuation of the friction brake comprises switching or engaging and then releasing the friction brake. After releasing or engaging, the drive part experiences no friction brake resistance and could, for example, move in a driven manner. This achieves in a simple and reproducible way that the surfaces of the friction partners are pressed against one another, causing particles to be released from the surfaces due to pressure, and then the friction surfaces are released again in a contactless state, whereby the released particles or the fluids heated by friction can detach from the friction surfaces, e.g. detach, fall off or evaporate. Surface components are thus removed after the friction brake is released.

[0047] For example, the friction brake is applied before the onset of slipping, for which the friction brake is already in the applied but no longer released state. For example, the application of the friction brake brings the friction surfaces of the friction brake into a chemically and physically conditioned state.

[0048] For example, the friction brake may be actuated exactly once or several times before the measurement interval. For example, the control unit can specify the time of actuation of the friction brake relative to the start of the measurement interval. For example, the time of actuation of the friction brake relative to the start of the measurement interval may be a few seconds before the start of the measurement interval, for example, one second before the start of the slipping condition.

[0049] For example, this ensures that the friction brake is in a comparable condition for all measurements taken before the actual measurement begins—namely, the conditioning condition of the friction brake. For example, the conditioning condition of the friction brake always ensures an identical or comparable initial condition immediately before the measurement begins. The same, or at least essentially the same, conditioning condition can be achieved for all different conditions before the sensor measurement begins, regardless of the respective condition of the friction brake before the conditioning condition or before actuation. This allows, for example, the findings obtained from the sensor measurement values ​​to be better and more meaningfully comparable.

[0050] For example, the conditioning state is achieved in various possible ways, for example by actuating the friction brake, e.g. via a braking time or braking duration that can be specified or predetermined via the control device, or a predetermined angle of rotation that can be specified, e.g. predetermined, or via a predetermined number of brake changes "on" / "off" or actuation or switching operations of the friction brake.

[0051] In this way, parameters of the friction brake that affect the measurement, such as moisture on the friction surfaces, water, oil, grease, etc., dirt, dust, particles on the friction surfaces, surface temperature of the friction surfaces, are conditioned or balanced in such a way that a comparable condition of the friction brake is achieved before the start of each measurement.

[0052] For example, the drive unit comprises an electric motor, with the electric motor's motor current serving as a measurement parameter. For example, the electric motor serves to drive the drive part, so that the electric motor works against the effect of the friction brake when driving to reach the slipping state, thus correlating the motor current with the braking force provided by the friction brake.

[0053] For example, it is possible to reliably and easily map the current or effective braking torque of the friction brake using the regularly and easily measurable motor current that the electric motor draws when the friction brake is applied.

[0054] For example, the torque or counter-braking torque derived from the absorbed motor current serves as the basis for assessing the current braking effect or the currently available maximum braking torque of the friction brake. For example, it is possible to indirectly calculate the current braking torque of the friction brake from the measured motor current absorbed by the electric motor.

[0055] For example, a processing instruction for processing the multiple sensor measured values ​​is stored in the control device in order to determine the braking effect of the friction brake in its actual state. For example, the processing instruction includes an algorithm and / or, for example, computer software.

[0056] For example, the processing rule includes a mathematical and / or a statistical processing rule.

[0057] For example, the processing instructions subject sensor measurement values ​​recorded by the sensor devices to mathematical processing or evaluation.

[0058] For example, the processing instruction is used to create a calculated value of the measurement parameter, for example by averaging based on several individual sensor measurements.

[0059] For example, the processing specification includes different mathematical methods for processing the sensor measured values.

[0060] For example, the processing instruction is used to calculate an arithmetic, geometric and / or a root mean value based on the measured sensor values.

[0061] For example, the processing specification includes a programmable filter, e.g., for averaging, such as a torque average, based on a braking torque of the friction brake or on a counter torque to the braking torque of the friction brake.

[0062] For example, the processing rule includes a weighted averaging method. For example, the processing rule uses the polynomial method or another mathematical method to generate a representative value from several different individual values, such as the sensor measurements.

[0063] For example, according to the processing specification, so-called time triggering is performed. For example, according to the processing specification, mathematical functions are used for gradient detection based on the temporal progression of the braking torque in the slipping state of the friction brake. For example, the processing specification includes a mathematical derivation of the measured value function or simple gradient detection, with the function being formed based on the recorded sensor measurements.

[0064] The invention also relates to a method for determining a braking effect of a friction brake of a device according to one of the embodiments described above.

[0065] For example, all types of friction brakes can be tested using the method with regard to determining the braking effect of the friction brake.

[0066] For example, the device comprises a drive unit for driving a movable drive part of the device and the switchable friction brake, wherein the moving drive part can be braked with the friction brake by friction between friction partners and / or can be held stationary in a static state of the drive part, wherein the device comprises sensor means and a control device for operating the device, wherein the control device processes a sensor measured value of a measurement parameter that can be detected by the sensor means, and wherein, when the friction brake is in braking action and starting from the static state of the drive part, an increase in the drive dimension of the drive unit takes place against the effect of the friction brake in braking action,until, due to the effective drive dimension, the drive part moves from the static state into a slipping state of the moving drive part which is temporally subordinate to the static state, whereby in the slipping state of the drive part a braking torque of the friction brake on the driven movement of the drive part is maintained.

[0067] Over a predetermined measuring interval, which lies within a range in which the drive part is in the slipping state, several sensor measured values ​​are recorded with a time offset for a predetermined measuring parameter, wherein the measuring parameter correlates with a braking torque of the friction brake acting on the driven drive part during the slipping state in the measuring interval, and wherein a braking effect of the friction brake in an actual state of the friction brake on the drive part is determined on the basis of the several sensor measured values ​​of the same measuring parameter.

[0068] For example, it is advantageously possible to characterize the actual state of the friction brake.

[0069] For example, the current actual state of the friction brake is determined during slipping and reflects a holding effect of the friction brake in the static state of the drive part or allows conclusions to be drawn about the static holding effect of the friction brake.

[0070] For example, the braking effect of the friction brake is determined based on the recording of sensor measured values ​​that represent or determine the braking torque of the friction brake.

[0071] For example, the braking effect of the friction brake is determined on the basis of sensor measurement values ​​that determine a drive dimension of the drive unit during the slipping state of the drive part.

[0072] For example, a drive dimension of the drive unit during the slipping state of the drive part is characterized by the acceleration of the drive part and / or the speed of the drive part and / or the absolute distance or the absolute angle of rotation of the drive part.

[0073] For example, sensor measurements are recorded to determine the actual state of the friction brake when the acceleration of the drive part of the drive unit is less than 500 mm / s, for example. 2 or e.g. less than 300 mm / s 2 or less than 100 mm / s 2 or less than 50 mm / s 2 10 mm / s 2 or e.g. less than 5 mm / s 2 or less than 3 mm / s 2 or less than 2 mm / s 2 is.

[0074] For example, the sensor measured value is the motor current of an electric motor in the drive unit. The higher the current consumption of the drive unit's electric motor, the greater the current braking torque of the friction brake. This allows the motor current to be used, for example, to directly determine the braking torque of the friction brake.

[0075] For example, a torque value of the drive unit is calculated based on the sensor measurements. For example, the torque value of the drive unit at the time of the torque measurement correlates with the braking torque of the friction brake at the time of measurement.

[0076] For example, an average torque value of the drive unit is calculated based on the sensor measurements. For example, several sensor measurements are recorded, and an average of the sensor measurements is calculated from them. For example, the average of the sensor measurements correlates with an average torque value, which allows conclusions to be drawn about the braking torque of the friction brake and determines the actual state of the friction brake.

[0077] For example, at intervals during an operating period of the friction brake, the actual state of the friction brake is determined in relation to its braking effect on the drive part and a history of the various determined actual states is used as a basis for evaluating the friction brake with regard to a forecast of the future function of the friction brake.

[0078] For example, the actual state of the friction brake is compared over a period of operation of the device or over the course of the device's operation, e.g. at regular intervals, e.g. once an hour, once a day, once a week, with a reference state of the friction brake, e.g. when the friction brake is in a new condition. For example, on this basis, a regular test of the friction brake is carried out during the useful life of the device or the friction brake. The regularly recorded actual state values ​​can allow a forecast to be made, for example when a braking torque of the friction brake is expected to fall below a target value. This enables improved planning with regard to the functional reliability of the friction brake and thus the operation of the device. For example, repair, maintenance and / or downtimes for a device such as a machine tool can be better estimated.

[0079] For example, a history of the various determined actual states is used to determine a point in time, at which point in time a limit value of the braking effect of the friction brake is expected.

[0080] For example, various actual states of the friction brake derived from the sensor measurements (e.g., one actual state is determined daily) are subjected to a trend analysis. This allows, for example, after one week, two weeks, or more, to determine an expected state of the actual state of the friction brake at which a limit value regarding the actual state of the friction brake is likely to be reached. This procedure serves, for example, for the early detection of wear or for the detection of wear dynamics and, if necessary, for determining an expected failure time of the friction brake.

[0081] For example, based on trend analysis, better planning of the use of a device such as a machine tool can be achieved. Character description

[0082] Further features and advantages of the invention are explained in more detail with reference to the figures.

[0083] In detail: Fig. 1 a measurement diagram for recording a braking behavior of a friction brake according to a method for determining a braking effect of the friction brake and Fig. 2 a device with a drive unit for driving a drive part and with a friction brake.

[0084] The measurement diagram according to Fig. Figure 1 illustrates a friction brake test performed to assess the actual condition of the friction brake. The actual friction brake test is preceded by a preliminary test, which, for example, lies within a first phase described below.

[0085] The measurement diagram according to Fig. 1 is structured as an xy-diagram and has an x-axis representing a time axis and a y-axis on which the torque of the respective friction brake is plotted. For example, torque and time are assigned SI units. For example, the x-axis is assigned the unit seconds (s), and the y-axis is assigned the unit newton meters (Nm).

[0086] The respective torque of the friction brake refers to a braking torque caused by the friction brake in an active or braking state of the friction brake, which corresponds to a closed state of the friction brake.

[0087] In the measurement diagram according to Fig. 1 shows the measured values ​​M1 to M30 determined before and during a brake test with the friction brake to be tested.

[0088] For example, based on a polynomial method, the concrete or absolute measured values ​​M1 to M30 are filtered and displayed in the measurement diagram, for example, according to a curve K calculated in this way.

[0089] The measured values ​​M1 to M30 and the measurement curve K are in Fig. 1 is shown schematically.

[0090] The braking test is divided into several time phases, here as an example into three time phases.

[0091] A first phase lies between the times x0 at time "zero" or a starting time x0 and a later time x1. At the starting time x0, the friction brake is closed. For example, at the starting time x0, the drive unit is not actively driving or

[0092] The first phase x0 to x1 covers a static range of the friction brake, which represents a state of the closed friction brake with statically relative friction partners and force-induced pressed together.

[0093] In the first phase, with the friction brake's friction partners pressed against each other, the measured values ​​M1 to M6 are recorded consecutively at successive, spaced-apart points in time between X0 and X1 with x1 > x0. For example, there are five measurement points for the respective measured values ​​M1 to M5 between times x0 and x1.

[0094] In the first phase, the drive power of the drive unit is gradually increased. In this phase, the six measured values ​​M1 to M6 are recorded, for example, by sensors. The measured values ​​M1 to M6 represent an increasing braking torque of the friction brake, with M6 > M5 > M4 > M3 > M2 > M1.

[0095] A second phase, comparatively short to the first phase, exists between time x1 and a later time x2. The second phase is, for example, a transition phase. Within the second phase, there is, for example, exactly one measured value M7. For example, two or more measured values ​​are also possible in the second phase. Within the second phase, the slope of the measurement curve K is not "zero" or approximately "zero".

[0096] The second phase represents a phase of the friction brake in which, due to increasing drive power from the drive unit, the friction brake is caused to slip and one friction partner slips. In the process, the previously static friction partners leave their static state. In the second phase, one friction partner moves relative to the other friction partner at a comparatively low relative speed, e.g., with relatively low acceleration. In the second phase, the friction partners of the friction brake, which are pressed against one another, move from the static state into a slipping state, and a drive part that can be driven by the drive unit moves accordingly. In the process, a static holding torque is overcome between time x1 and time x2.

[0097] The first and second phases are not used to assess the braking effect of the friction brake or are not used for the brake test. The first and second phases are not relevant for the brake test.

[0098] The braking test in the time interval between x2 and x3 refers solely to a dynamic braking torque measurement.

[0099] The third phase follows the second phase and follows, for example, according to Fig. 1 directly or via a short intermediate phase (not shown) to the second phase. In the third phase, between times X2 and X3, the dynamic braking torque measurement takes place.

[0100] A starting point of the measuring interval at time x2 is specified, for example, by determining the “zero” gradient of the torque of the friction brake or the “zero” gradient of the measuring curve K. This is the case, for example, with a tolerance from time x2.

[0101] For example, the gradient "zero" is an approximate zero gradient. For example, in the measurement interval, the gradient determined from the measured values ​​over the measurement period lies within an upper limit, such as a maximum limit, and a lower limit, such as a minimum limit.

[0102] This is followed by the third phase or the measuring interval between x2 and x3 up to time x3. The third phase, which concerns the actual friction brake measurement, represents a dynamic measuring range of the braking torque measurement. Within the third phase, with the drive unit actively driving, a predefined number of measured values ​​are recorded, for example, one hundred measured values ​​are recorded. Fig. 1 shows the measured values ​​M8 to M30 schematically.

[0103] The end of the measuring interval at time x3 is reached when a predefined number of measurements, for example 100 measurements of a braking torque of the friction brake, have been recorded.

[0104] For example, to evaluate the friction brake, which refers only to the third phase, the measurement curve K is considered.

[0105] A condition of the friction brake “not OK” is determined, for example, when the measurement curve K reaches or exceeds an upper or maximum limit value of a braking torque or torque Bmax within the third phase between x2 and x3.

[0106] A condition of the friction brake “not OK” is determined, for example, when the measurement curve K reaches or falls below a lower or minimum limit value of a braking torque or torque Bmin within the third phase between x2 and x3.

[0107] A condition of the friction brake “not OK” is determined, for example, when the measuring curve K reaches or exceeds an upper or maximum limit value of a braking torque or torque Bmax within the third phase between x2 and x3 and / or when the measuring curve K reaches or falls below a lower or minimum limit value of a braking torque or torque Bmin within the third phase between x2 and x3.

[0108] For example, within the third phase, below the minimum limit value of the braking torque Bmin, there is a tolerable minimum limit braking torque Bmin tolerance, which can be used to evaluate the actual condition of the friction brake.

[0109] For example, within the third phase, above the maximum limit value of the braking torque Bmax, there is a tolerable maximum limit braking torque Bmax tolerance, which can be used to evaluate the actual condition of the friction brake.

[0110] Fig. Figure 2 shows a device 1 with a switchable friction brake 2, which is a mechanical brake, and with a drive unit 3 for driving a drive part 4. The drive part 4, such as a rotating driven spindle, is in Fig. 2 is concealed by external housing parts of the device 1. For example, the device 1 serves to drive a machine tool. For example, the drive unit 3 is an electric motor drive for the electric motor-driven rotating drive of the spindle.

[0111] Inside the device 1 are Fig. 2 non-visible friction partners of the friction brake, sensor means and a control device for operating the device are housed.

[0112] For example, the drive effect is transmitted from the drive unit 3 to the drive part 4 via a gear. List of reference symbols 1 device 2 friction brake 3 Drive unit 4 Drive part QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] EN ISO 16092-2:2020 [0008, 0019]

Claims

[1] Device with a drive unit for driving a movable drive part of the device and with a switchable friction brake, wherein the moving drive part can be braked by the friction brake by friction between friction partners and / or can be held stationary in a static state of the drive part, wherein the device comprises sensor means and a control device for operating the device, wherein the control device processes a sensor measured value of a measurement parameter that can be detected by the sensor means, and wherein, when the friction brake is in braking action and starting from the static state of the drive part, an increase in a drive dimension of the drive unit takes place against the effect of the friction brake in braking action,until, due to the effective drive dimension, the drive part moves from the static state into a slipping state of the moving drive part which is temporally subordinate to the static state, whereby in the slipping state of the drive part a braking torque caused by the friction brake is maintained on the driven movement of the drive part, , characterized bythat the control device and the sensor means are designed such that over a predetermined measuring interval, which lies within a range in which the drive part is in the slipping state, a plurality of sensor measured values ​​can be recorded with a time offset for a predetermined measuring parameter, wherein the measuring parameter correlates with a braking torque of the friction brake acting on the driven drive part during the slipping state in the measuring interval in order to determine a braking effect of the friction brake on the drive part in an actual state of the friction brake on the basis of the plurality of sensor measured values ​​of the same measuring parameter. [2] Device according to claim 1, characterized by that the measuring interval is defined by a measuring path that the drive part travels in the slipping state. [3] Device according to claim 1 or claim 2, characterized bythat the measuring interval is defined by a measuring time which lies within a period in which the drive part is in the slipping state. [4] Device according to one of the preceding claims, characterized by that the control device and the sensor means are designed to determine a starting time of the slipping state of the drive part, wherein the determination of the braking effect of the friction brake takes place only after the starting time of the slipping state of the drive part and after the expiry of a first temporal phase of the slipping state of the drive part following the starting time. [5] Device according to one of the preceding claims, characterized by that the control device and the sensor means are designed in such a way that the number of the multiple sensor measured values ​​offset in time can be specified. [6] Device according to one of the preceding claims, characterized bythat the measuring interval lies within a range within which the rotating drive part completes one revolution. [7] Device according to one of the preceding claims, characterized by that the control device and the sensor means are designed in such a way that the friction brake assumes a predeterminable conditioning state when actuated before the measuring interval. [8] Device according to one of the preceding claims, characterized by that the drive unit comprises an electric motor, wherein a motor current of the electric motor serves as a measuring parameter. [9] Device according to one of the preceding claims, characterized by that a processing instruction for processing the multiple sensor measured values ​​is stored in the control device in order to determine the braking effect of the friction brake in an actual state of the friction brake. [10] A method for determining a braking effect of a friction brake of a device according to one of the preceding claims, wherein the device comprises a drive unit for driving a movable drive part of the device and a switchable friction brake, wherein the moving drive part can be braked by the friction brake through friction between friction partners and / or can be held stationary in a static state of the drive part, wherein the device comprises sensor means and a control device for controlling the operation of the device, wherein the control device processes a sensor measured value of a measurement parameter that can be detected by the sensor means, and wherein, when the friction brake is in braking action and starting from the static state of the drive part, an increase in a drive dimension of the drive unit takes place against the effect of the friction brake in braking action,until, due to the effective drive dimension, the drive part moves from the static state into a slipping state of the moving drive part which is temporally subordinate to the static state, whereby in the slipping state of the drive part a braking torque of the friction brake on the driven movement of the drive part is maintained, , characterized by that over a predetermined measuring interval, which lies within a range in which the drive part is in the slipping state, a plurality of sensor measured values ​​are recorded with a time offset for a predetermined measuring parameter, wherein the measuring parameter correlates with a braking torque of the friction brake acting on the driven drive part during the slipping state in the measuring interval, and that on the basis of the plurality of sensor measured values ​​of the same measuring parameter, a braking effect of the friction brake in an actual state of the friction brake on the drive part is determined. [11] Method according to claim 10, characterized by that a motor current of an electric motor of the drive unit is determined as the sensor measured value. [12] Method according to one of claims 10 to 11, characterized by that a torque value of the drive unit is calculated based on the sensor measurements. [13] Method according to one of claims 10 to 12, characterized by that an average torque value of the drive unit is calculated based on the sensor measurements. [14] Method according to one of claims 10 to 13, characterized by that at intervals during an operating period of the friction brake, the actual state of the friction brake is determined in relation to its braking effect on the drive part and a history of the various determined actual states is used as a basis for evaluating the friction brake with a view to predicting a future function of the friction brake. [15] Method according to claim 14, characterized bythat a course of the various determined actual states is used to determine a point in time, at which point in time a limit value of the braking effect of the friction brake is expected.

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