DEVICE AND METHOD FOR MONITORING A TABLET MACHINING MACHINE, PREFERABLY DURING OPERATION, BY MEANS OF A MEASURING DEVICE ATTACHED TO A PRESS STAMP

Description

[0001] The invention preferably relates to a press die for a tableting machine. The press die preferably includes a measuring device that is energy-autonomous and can function independently of the power supply of the tableting machine.

[0002] Furthermore, the invention preferably relates to a tableting machine and a system which includes the above-mentioned press plunger.

[0003] Furthermore, the invention relates to a method for monitoring a tablet press with the press die according to the invention during operation. The measuring device of the press die preferably comprises a sensor, a processing unit, a communication unit, and a storage unit. The sensor of the measuring device records physical or chemical measurements. Subsequently, the communication unit of the measuring device preferably transmits the recorded sensor measurements to a programmable logic controller (PLC) of the tablet press and / or to a data processing unit, and / or the recorded sensor measurements are preferably stored on the storage unit of the measuring device. State of the art

[0004] Tableting machines are primarily used for the industrial-scale production of tablets. Tableting machines are based on the principle that a die is first filled with a powder mixture to be tableted. The mixture is then compressed into a tablet by the interaction of an upper and lower punch. Modern tableting machines with multi-tools can produce several million tablets per hour.

[0005] The large number of pressing operations leads to wear on the pressing tools and can also cause wear on various components of the tableting machine. Furthermore, during operation, machine parameters may become less than ideal for the pressing process due to changes in ambient temperature and / or vibrations. Both wear and unsuitable operating parameters can therefore lead to faulty pressing operations and damage components of the tableting machine as a whole. Various types of measuring devices are used in the prior art to monitor such faults. A sensor is an essential component of such a measuring device.

[0006] A sensor (also called detector, transducer, or measuring probe) is a technical component and preferably the first element of a measuring chain in a measuring device. A sensor can qualitatively or quantitatively determine physical (e.g., heat quantity, temperature, humidity, pressure, sound field quantities, brightness, acceleration) or chemical (e.g., pH value, ionic strength, electrochemical potential) properties and / or the material composition of its environment. These quantities are detected by means of physical or chemical effects and converted into a further processable electrical signal. Sensors within machine tools, especially forming machines such as presses or punches, are well known.

[0007] German patent application DE 10 2006 002 359 B4 discloses a tableting machine in the form of a rotary press, which has a temperature sensor in the immediate vicinity of its die. The sensor is stationary, not rotating with the rotor, and is, for example, mounted on the machine frame. The sensor monitors the production process, in particular by recording the temperature values ​​of the tablets being produced.

[0008] A disadvantage of this type of tableting machine is that it can only record one physical property, namely the temperature inside the press. Furthermore, the temperature can only be measured at a stationary point inside the press.

[0009] German patent DE 10 2005 051 567 B4 discloses a tableting machine – a rotary press – and a method for measuring the displacement of a press ram. In this process, the press rams of the rotary press are equipped with markers. As the press rams rotate, these markers pass a stationary sensor (located outside the rotor). This sensor records the changes in the markers' positions, which are then evaluated.

[0010] Document DE 195 02 596 C2 describes sensors and measuring devices for monitoring the tableting process. Force sensors are attached to both an upper and a lower pressure roller to determine the pressing force values ​​of a pair of punches. In conjunction with the rotor position, these measurements and previously determined machine parameters are used to measure and calculate displacement-pressing force relationships.

[0011] The disadvantage of this arrangement is that the pressing force is not measured directly at the press rams. Components of varying strength and stiffness (pressure roller, pressure roller bearings, press stations) exist between the sensor and the press ram. These components affect the quality of the force measurement. Another disadvantage is that this sensor arrangement can only record one physical property: the force exerted by the press ram on the pressure roller.

[0012] A crucial element for the functionality of tableting machines is the press die; therefore, it is essential to monitor it closely. Forming machines, particularly presses, are known in the prior art that include a sensor designed to monitor pressing forces on a press die. However, the known designs for monitoring pressing forces on press dies have significant disadvantages, as will be shown below.

[0013] Publication DD 294 457 A5 describes a sensor for force measurement on presses. In this system, a force sensor is integrated into a piston body. A press ram is attached to this piston body, so that the force sensor is positioned above the ram (in the case of the upper ram) or below it (in the case of the lower ram). The force sensor is wired to a power source via a corresponding bore in the piston body.

[0014] The disadvantage of force measurement with such an arrangement is that its implementation is practically impossible for tablet presses designed as rotary presses. Press rams in rotary presses are guided directly by cams. It is impractical to hold each press ram in a piston body and, moreover, to ensure an external power supply for the press rams. Furthermore, this sensor arrangement described in DD 294 457 A5 is intended solely for determining forces during a pressing operation. The arrangement described in the document cannot detect forces that may occur in a press ram before or after a pressing operation. Moreover, the acceleration or temperature of the press ram cannot be determined solely by the sensor's position.

[0015] This arrangement also has disadvantages for eccentric presses. For example, the press ram must be held in a specifically designed piston body, which means, among other things, that it is impossible to measure the varying loads that occur partially within the press ram. These can be detrimental, for instance, if the press ram does not act perpendicularly on the powder material being compressed.

[0016] JP S60 42492 U discloses a press die according to the preamble of claim 1 with a detector configured as a strain gauge and attached to the outside of the die body's shaft. The strain gauge is attached to the die body's shaft to obtain information about the force acting on the die body. The detector's measurement data can be transmitted via a radio transmitter to an external transmitter, which is connected to the detector via a wire.

[0017] Document DE 101 35 283 C2 discloses a method for compressing powder material.

[0018] For different pressing forces, deformations of the die plate are measured or calculated. The force measurement sensors are in direct contact with the press rams and are mounted above (upper ram) and below (lower ram) the press rams. The sensors are attached to the bearing surface of the ram heads.

[0019] Such a method is also practically unfeasible for tablet presses designed as rotary presses, since in rotary presses the press rams are guided by cams. The rams come into direct contact with the press rollers at their ram heads, making it impractical to mount a sensor on the ram head.

[0020] Therefore, there is a need for improvement in the provision of measurement techniques that can be easily and robustly integrated into a tableting machine or process and enable continuous measurement and monitoring of process parameters. Object of the invention

[0021] The object of the invention is to eliminate the disadvantages of the prior art and to provide a device and a method for tableting machines to determine physical and / or chemical properties directly and continuously on and / or in a press punch. In particular, an object of the invention was to provide means for integrating measuring devices into a tableting machine, which are characterized by a high degree of flexibility and accuracy, in order to enable continuous measurement and / or monitoring of a large number of process parameters with respect to a press punch in a tableting process. Summary of the invention

[0022] The problem according to the invention is solved by the features of independent claims 1 and 6.

[0023] Advantageous embodiments of the invention are described in the dependent claims.

[0024] The invention relates to a press die for a tableting machine, wherein the press die has a measuring device that is energy-autonomous and functional independently of a power supply to the tableting machine, and wherein the measuring device has a sensor for recording physical and / or chemical properties. The press die is characterized in that the measuring device is integrated within the press die body and comprises a sensor, a communication unit, a storage unit, an energy storage device, and a processing unit, wherein the measured values ​​obtained as raw data can be processed by means of the processing unit.

[0025] Because the press ram of the tablet press incorporates a measuring device, measured values ​​directly related to this press ram can be recorded without having to factor in the influence of other components. Furthermore, the device can be easily installed without requiring a connection to the tablet press's power supply. Additionally, the measuring device is advantageously not fixed to a single location on the tablet press due to the rotating ram in the case of a rotary press. This allows physical or chemical properties (e.g., temperature measurement) to be continuously recorded throughout the entire rotor rotation of a rotary press. Therefore, the present invention advantageously enables, in contrast to known devices in the prior art, the recording of measured values ​​before, during, and after a pressing process.

[0026] For the purposes of the invention, the tableting machine is preferably a rotary press or an eccentric press.

[0027] According to the invention, the press die is preferably designed to have a die head, a die shank, and a die tip. Those skilled in the art are familiar with the terms die head, die shank, and die tip. The measuring device is preferably enclosed in or incorporated within the die shank.

[0028] The measuring device includes a sensor for recording the physical and / or chemical properties of the press ram and / or its environment. Physical properties are defined, for example, by heat quantity, temperature, humidity, pressure, sound field quantities, brightness, and acceleration. Chemical properties include, for example, pH value, ionic strength, and electrochemical potential. These properties can be recorded qualitatively or quantitatively as measured values.

[0029] The measuring device preferably comprises several different sensors that simultaneously record different physical or chemical properties (of the press punch and / or its environment). The combination of several different measured values ​​advantageously leads to increased accuracy in assessing the condition of components of the tableting machine or the production process.

[0030] In a preferred embodiment of the invention, the press punch is characterized in that the measuring device includes a sensor, in particular for recording a force, a temperature, or an acceleration of the press punch and / or its surroundings. By recording these values, it is advantageously possible to make a statement about the wear and functionality of the press punch and / or the tableting machine in general.

[0031] In a further preferred embodiment of the invention, the press ram is characterized in that the measuring device has several sensors which are configured to measure the pressing force, the temperatures of the press ram and ram tip, and the linear and rotational accelerations of the press ram. By measuring these values, it is advantageous to be able to make statements about the pressing process, the functionality of the press ram, and wear in general.

[0032] In a preferred embodiment, the measuring device includes an active sensor. Active sensors generate a voltage due to their measuring principle and do not require any auxiliary electrical power. Examples of active sensors include thermocouples, light sensors, or pressure sensors. The integration of active sensors advantageously results in lower energy consumption.

[0033] In another embodiment, the sensor of the measuring device is designed as a passive sensor. Passive sensors contain passive components whose parameters are changed by the measured quantity. These parameters are converted into electrical signals by primary electronics. This requires an externally supplied auxiliary energy source. Examples of passive sensors include: load cells, resistance thermometers, strain gauges, and magnetic field sensors (Hall probes). Passive sensors advantageously provide particularly accurate measurement results.

[0034] In a preferred embodiment of the measuring device, the sensor is a temperature sensor. By measuring the temperature, conclusions can be drawn about the function of the ram guide and lubrication, which can provide information about wear. Similarly, by measuring the temperature and temperature profile of the ram tip, conclusions can be drawn about a pressing process.

[0035] Furthermore, monitoring the temperature of the press die and / or its surroundings allows for inferences to be drawn about the temperature of the materials being compressed. This is highly relevant in tableting processes for temperature-sensitive materials. Compression of these materials is only possible within specific temperature ranges. Therefore, the compression process can be adjusted and / or even terminated based on the recorded values ​​if these values ​​exceed or fall below a certain threshold.

[0036] Furthermore, recorded temperature values ​​of the press ram can be advantageously used to monitor or control compression or elongation of the press ram due to temperature fluctuations.

[0037] Temperature can preferably be measured in many ways using different sensors and measuring devices. Preferred sensors for temperature measurement are listed below. However, the invention is not limited to sensors in general, their operation, or their design.

[0038] A preferred temperature sensor comprises an NTC thermistor, i.e., a negative temperature coefficient thermistor. This type has a negative temperature coefficient, so as the temperature increases, its resistance decreases and a higher current flows. However, PTC thermistors, i.e., positive temperature coefficient thermistors, can also be used, which have a positive temperature coefficient, so as the temperature increases, their resistance increases and a lower current flows.

[0039] In another preferred embodiment, the temperature sensor is designed as a semiconductor temperature sensor. It generates an electrical quantity proportional to the absolute temperature. This electrical quantity can preferably be represented analogously or digitally.

[0040] In another preferred embodiment, the temperature sensor comprises a temperature probe with a quartz crystal as the measuring element. The resonant frequency of the oscillating quartz changes depending on the temperature and can be measured very precisely. According to the invention, the temperature probes are preferably distributed on the outer surface of the press die body and particularly preferably within the press die body.

[0041] In another preferred embodiment of the temperature sensor, it is implemented as a thermocouple. Thermocouples consist of a pair of metallic conductors made of different materials, joined at one end. They convert a temperature difference into an electrical voltage (Seebeck effect).

[0042] Other alternative temperature sensors according to the invention may include ferromagnetic temperature sensors.

[0043] In a preferred embodiment of the measuring device, the sensor is a displacement sensor or distance sensor. Advantageously, a displacement sensor enables the precise determination of the position of a press punch in the tableting machine, so that positional anomalies can be detected immediately. Similarly, geometric changes in individual elements of the tableting machine can be detected.

[0044] In a tableting machine's pressing process, the upper and lower dies preferably travel a converging path. By measuring this path using displacement or distance sensors, a ratio between pressing force and path can preferably be determined (in combination with a force sensor), thus advantageously allowing the derivation of properties of the pressing compound, such as elasticity, plasticity, and porosity.

[0045] Determining a position, distance, or path can be achieved using a variety of measurement principles and, consequently, a variety of sensor arrangements. The invention is therefore not limited to the path and distance sensors listed in this document.

[0046] It is preferred that the measuring device includes both direct and indirect measuring principles for determining the position, distance, or displacement. Furthermore, the measured values ​​can also preferably be obtained by integrating all conceivable linear displacement measuring systems into the press die.

[0047] In another preferred embodiment, measured values ​​can be linked together to improve accuracy and the information provided about a condition. For example, the exact rotor position in connection with rotary presses helps to improve displacement measurement with the accelerometers.

[0048] A potentiometer encoder is used in a preferred embodiment of the displacement sensor. The potentiometer encoder is an electrical resistive component whose resistance values ​​can be changed mechanically (by rotation or displacement). According to the invention, the potentiometer encoder is integrated into a press die in such a way that its resistance changes with each rotation of the entire press die.

[0049] Strain gauges, which are used in an alternative embodiment of the displacement sensor according to the invention, follow a similar principle. A strain gauge changes its electrical resistance through changes in length and cross-section. Bridge circuits are preferably used to measure resistances. They can be used for the absolute determination of a resistance or for determining a relative change in resistance. When measuring with strain gauges, as already mentioned, the relative change in resistance is measured. Those skilled in the art are familiar with the design of the bridge circuit in connection with the measurement of resistance changes of strain gauges as a quarter bridge, half bridge, and full bridge. A strain gauge can preferably be used to detect the longitudinal expansion of a press ram.

[0050] Another preferred displacement sensor comprises a capacitive sensor. The capacitive sensor consists of two mutually insulated metallic parts. Together with the object being measured, it forms a capacitor with variable capacitance. The measurement effect is based on a geometric change in the distance between the two capacitor surfaces or a lateral displacement of these surfaces, which leads to a change in the effectively effective capacitor area.

[0051] Another embodiment of a displacement sensor can, for example, preferably be an inductive sensor. Inductive sensors generally operate with an inductor (open coil), generating a magnetic field which is altered by an object. This measuring principle advantageously allows for contactless and wear-free measurement of angles, displacements, distances, and velocities. According to the invention, several coils are preferably used.

[0052] In a further preferred embodiment, the measuring device comprises a force sensor. The invention is not limited to the force sensors listed below. Any force measurement device that can be meaningfully integrated into a press die is conceivable to enable its use for measuring pressing force. Preferably, force sensors are designed as pressure sensors.

[0053] In a preferred embodiment of the measuring device, the sensor comprises a pressure sensor. It has been shown that a pressure sensor within the measuring device provides valuable insights into the wear of press rams. Furthermore, maximum forces can be determined using pressure sensors, which, for example, must not be exceeded to prevent overloading.

[0054] The invention can preferably be aimed at determining pressing forces and pressing force profiles. The focus of the determination can be, for example, forces within a press ram that occur even before the press ram strikes the pressure rollers.

[0055] Depending on the powder and filling material being compressed, compression can occur even during the downward stroke of a rotary press. This is undesirable, but unavoidable. Furthermore, with incorrect settings, the upper ram can be pressed against the upper pressure roller or lift cam of a rotary press by the lower ram.

[0056] By measuring the pressing force profile during a complete rotation of a tablet press designed as a rotary press, effects / forces become apparent that were previously unmeasurable using state-of-the-art methods. This allows, among other things, the detection of wear on press rams and cam tracks that is otherwise inaccessible through measurement. Such measurements can reveal the forces generated when the press ram strikes the pressure roller and how the pressing force develops with different materials, because direct measurement is possible.

[0057] Continuous monitoring of potential wear on the press rams or cam tracks allows for significantly improved quality assurance. On the one hand, early replacement may be advisable. On the other hand, operating parameters can be adjusted to minimize progressive wear.

[0058] Another preferred pressure sensor is a piezoresistive pressure sensor. Piezoresistive pressure sensors utilize metallic strain gauges or pressure-sensitive semiconductor chips. The following piezoresistive sensor technologies are familiar to those skilled in the art: ceramic thick-film sensors, metal thin-film sensors, silicon pressure sensors, and piezoresistive silicon sensors.

[0059] Another preferred pressure sensor is a piezoelectric pressure sensor. In a piezoelectric sensor, an electrical voltage is generated in a crystal by pressure through charge separation (piezoelectric effect). Pressure causes ions to shift within the crystal, creating an electrical charge on the surface proportional to the force. This charge is then converted into a proportional electrical voltage by a charge amplifier. Any desired pressure can be set as the zero point of the charge amplifier by short-circuiting the charge, thus making pressure changes directly measurable.

[0060] In another preferred embodiment, the pressure sensor comprises a Hall element. This pressure sensor operates according to the Hall effect, whereby the magnetic field around the Hall element changes under pressure.

[0061] In an alternative preferred embodiment of the invention, the pressure sensor is a capacitive pressure sensor. Capacitive pressure sensors contain two capacitors diffused into a silicon chip. When pressure is applied, the distances between a diaphragm and two opposing capacitor plates change in opposite directions, so that the capacitances change accordingly. Preferably, the capacitors are part of an internal amplifier whose output signal depends on the difference in capacitances.

[0062] In another preferred embodiment, the sensor comprises an inductive pressure sensor. Inductive pressure sensors operate with an iron core connected to a diaphragm. Pressure changes generate a force on the diaphragm, causing it to move. This changes the position of the iron core in opposite directions in two coils: in one, the inductance increases, and in the other, it decreases. The difference can advantageously be determined electrically with high precision.

[0063] In a preferred embodiment of the invention, the sensor of the measuring device is configured as an accelerometer. Some of the sensors already mentioned can also, in a preferred embodiment, serve the purpose of an accelerometer.

[0064] The invention is not limited to the acceleration sensors named below and may well include further or different types of sensors for recording acceleration.

[0065] A preferred measuring device comprising an accelerometer can preferably be used to detect the displacement of a press ram. The use of an accelerometer is advantageously suited for this purpose because it does not require a baseline as a zero point or reference. Instead, the displacement is determined indirectly by integrating the measured acceleration. Nevertheless, sufficiently accurate information about the ram's position can be obtained, which can be used for both quality assurance of the pressed products and process optimization.

[0066] Furthermore, it is preferred to combine these measured values ​​with one or more additional measured values, preferably acquired by other measuring devices and / or sensors. This leads to improved accuracy and informative value. For example, in rotary presses, the exact rotor position can help to improve the displacement measurement using the accelerometers.

[0067] Furthermore, an acceleration sensor in conjunction with force measurement can be used to make statements about wear.

[0068] In a further preferred embodiment, a measuring device comprising an acceleration sensor is used to measure the impact of a press ram. Furthermore, the press ram can preferably be used to determine the force-displacement diagram. In particular, a displacement can be calculated from linear and rotational accelerations.

[0069] In accordance with the invention, a piezoelectric accelerometer is preferably used. Here, a piezoceramic sensor plate converts dynamic pressure fluctuations into electrical signals, which can then be processed accordingly. The pressure fluctuation is generated by a (seismic) mass attached to the piezoceramic and acts on the piezoceramic when the overall system is accelerated.

[0070] The acceleration sensor can also preferably be designed as a microelectromechanical system (MEMS). This sensor is a spring-mass system in which the "spring" is preferably a silicon bridge only a few micrometers (µm) wide. The mass is also preferably made of silicon. The deflection caused by acceleration of the press ram in the tableting machine (e.g., when the rotor starts up or when the direction of the ram's up-and-down movement changes) allows for a highly sensitive measurement of changes in electrical capacitance between the spring-mounted part and a fixed reference electrode. The electronics for evaluating this small change in capacitance are preferably integrated on the same integrated circuit.

[0071] In a preferred embodiment of the MEMS, a piezoresistive resistor is attached to a bending beam by ion implantation. The resistor's resistance changes according to the bending motion, thus allowing conclusions to be drawn about the acceleration. Ion implantation is known to those skilled in the art and is preferably used in semiconductor technology to modify the electrical properties of the base material (here: the bending beam).

[0072] In a further preferred embodiment, the accelerometer comprises a strain gauge. A force on a test mass is determined by measuring the deformation of the mounting (e.g., a rod) using the strain gauge. According to the invention, the press die can preferably be defined as the test mass. However, the test mass can also preferably be a mass other than the press die that comprises the measuring device.

[0073] In a further preferred embodiment of the accelerometer, the acceleration is determined via magnetic induction. When the test mass, suspended from a spring, moves, an electrical voltage is induced in a coil by a magnet. The test mass is preferably a mass other than the press die and comprises the measuring device.

[0074] In a preferred embodiment, the acceleration sensor is a Ferraris sensor. This measures the relative acceleration without a test mass using eddy currents.

[0075] In another particularly preferred embodiment, the measuring device comprises strain gauge full bridges, integrated MEMS sensors and temperature sensors.

[0076] According to the invention, the communication unit in the measuring device preferably serves to wirelessly transmit data recorded by the sensor. Accordingly, the communication unit is preferably a transmitting unit. In a further embodiment, the communication unit is particularly a transmitting unit and / or a receiving unit. Transmission preferably takes place via directed or omnidirectional electromagnetic waves, whereby the frequency band used can vary from a few hertz (low frequency) to several hundred terahertz (visible light), depending on the application and technology used. According to the invention, the following data transmission methods are preferably used: Bluetooth, WLAN, ZigBee, NFC, Wibree, or WiMAX in the radio frequency range, as well as IrDA and FSO (Full-Side Optical) in the infrared or optical frequency range.It has proven advantageous that transmitting via such a transmitter unit allows for wireless data transfer without loss of information during pressing processes in tablet presses, while maintaining a sufficient data transmission rate. In a further embodiment of the transmitter and / or receiver unit, this unit includes an antenna.

[0077] In one embodiment, wired transmission can be provided in addition to or as an alternative to wireless data transmission. In one embodiment, the measuring device includes analog and digital outputs (USB, RS232, fieldbus) for data transmission via signal conductors. The signal conductor preferably transmits the acquired measurement data to a programmable logic controller (PLC) of the tablet machine and / or to a data processing unit; furthermore, control commands are preferably transmitted to the outputs of the measuring device via the signal conductor.

[0078] The press die is characterized by the fact that the measuring device comprises a sensor, a communication unit, a storage unit, an energy storage unit, and a processing unit, wherein the measured values ​​obtained as raw data can be processed by means of the processing unit. Advantageously, data (high-resolution measurements) can be saved via the storage unit so that they can be used at a later time.

[0079] In accordance with the invention, the storage unit of the measuring device serves in particular to back up and store data. According to the invention, measurement data recorded by the sensor is preferably stored in the storage unit. The storage unit is preferably an electronic data carrier. Flash memory is particularly suitable for the compact integration of an electronic data carrier into the measuring device, although other data carriers may also be preferred.

[0080] In a further preferred embodiment, the measuring device comprises a computing unit. According to the invention, the computing unit of the measuring device preferably comprises a processor unit. The processor unit preferably comprises, in particular, a graphics processing unit (GPU) and / or a central processing unit (CPU). Both processors are known to those skilled in the art. Many computational operations on the raw data can thus preferably be performed decentrally on the measuring device itself. For example, the measurement signal can be sampled, particularly at a high frequency. Average values, as well as minimum and maximum values, can be determined from the raw data using the computing unit and transmitted via a communication unit to a data processing unit and / or a programmable logic controller (PLC) of the tableting machine. This advantageously saves energy and bandwidth.

[0081] In a further preferred embodiment, the measuring device is configured to process recorded measured values ​​as raw data using a processing unit and then store them in the measuring device's memory and / or transmit them, preferably via Bluetooth, to a data processing unit and / or programmable logic controller of the tableting machine. The processing of the raw data can, for example, involve converting the measurement data into a required format or reducing it to particularly relevant information (such as average values, exceeding defined thresholds for force / acceleration / temperature / distance, etc.).

[0082] Preferably, the measuring device includes a cable output from which a preconditioned measurement signal is output as a universal analog or digital signal (e.g. 0 - 10 V, serial).

[0083] In a preferred embodiment of the invention, various trigger options are available for the storage unit and processing unit of the measuring device to control the measurement data acquisition, for example, in particular after specific time intervals or when threshold values ​​(force / acceleration / temperature) are exceeded. This ensures that a data logger only saves data when certain events, such as a high load, occur. In this way, cumulative stress collectives in a stressed component can be recorded. The stored measured values ​​can be read out, for example, after completion of the measurement, using a data processing unit (e.g., a PC) and / or a programmable logic controller (PLC) of the tableting machine via a simple USB connection.

[0084] In a further preferred embodiment of the invention, the measuring device, preferably its processing unit, is configured for control and / or data access by a data processing unit and / or a programmable logic controller (PLC) of the tableting machine. For this purpose, control parameters for performing the measurement can be sent to the measuring device. These control parameters can relate, for example, to the type of measurement or a selection of active sensors (in the case of multiple sensors), the timing of the measurement, or instructions for processing or pre-evaluating the raw data.

[0085] The data processing unit can be, for example, a tablet computer, smartphone or a PC, preferably with a computer program product (application / “app”) installed on it for controlling and / or accessing the data.

[0086] Preferably, data exchange between the app and the measuring device is ensured via the communication unit of the measuring device, whereby the app preferably transmits control commands to the measuring device, which can be processed by the computing unit included in the measuring device.

[0087] In addition to controlling the measuring device, the app is primarily designed to access data from the measuring device (or [processed] measured values ​​are transferred via the communication unit of the measuring device to the communication unit of a tablet computer or smartphone) and to visualize and / or save this data.

[0088] Furthermore, the measuring device preferably has different transmission modes, preferably two or more, which differ in terms of bandwidth and power consumption.

[0089] A first transmission mode is preferably defined by direct communication between the measuring device and an external device (smartphone, tablet PC, or programmable logic controller of the tableting machine). For the purposes of the invention, this transmission mode is referred to as streaming. In particular, this transmission mode is characterized by a high data rate.

[0090] In a second transmission mode, the measured values ​​from the measuring device are preferably transmitted to a distribution unit. The distribution unit is connected to a multitude of external devices (smartphone, tablet PC, or programmable logic controller of the tableting machine), which can access the data from the distribution unit. This transmission mode is preferably referred to as broadcasting, where the measured values ​​are acquired with a high internal sampling rate (500 Hz), and a live average value as well as a minimum / maximum value are calculated from these values, so that a high data rate is not necessary. The distribution unit can preferably also be a data processing unit.

[0091] The following describes a specific embodiment and application of a preferred measuring device. The invention is not limited to this embodiment.

[0092] A preferred measuring device enables the time-synchronous transmission and storage of recorded measurement values ​​from two sensors with strain gauge bridges. Additionally, integrated MEMS sensors preferably measure rotational speed and three-axis acceleration. An integrated processor unit preferably processes the sensor data directly on the measuring device, thus advantageously significantly reducing the amount of data to be transmitted. The measuring device preferably enables simple and continuous process monitoring. The recorded measurement data and interpreted states are preferably transmitted to a distribution unit via Bluetooth, preferably Bluetooth Low Energy 4.2. A large number of measuring devices can preferably be connected to the distribution unit in a time-synchronous manner.

[0093] Under ideal conditions, the transmission range is up to 30 meters, and more than 50 devices can be connected to the distribution unit. Simultaneously, all measurement data is displayed and optionally saved in an application on a tablet computer or smartphone. The application is preferably used to set a calibration value for the measuring device and configure the outputs of a gateway. The measuring device is preferably powered by a Li-ion battery and charged via a USB power supply. The measuring device preferably has external dimensions of 50 mm x 13 mm x 9 mm. Furthermore, the measuring device preferably has a flash memory of up to 8 GB.

[0094] In a preferred embodiment, the measuring device comprises strain gauge sensors in addition to MEMS sensors, enabling the measurement of accelerations, rotational speeds, and orientation in addition to force measurement. Modern MEMS sensors include an integrated temperature sensor, allowing the temperature to also be measured by the device.

[0095] In a preferred embodiment of the invention, the measuring device is energy-autonomous. With regard to the invention, the measuring device can thus be used independently of the tableting machine's power supply. It has been found that energy-autonomous measuring devices are particularly easy to integrate into tableting machines that operate on the rotary principle. Moreover, if one sensor power source fails, only one sensor is affected, so that all sensors are independent of each other.

[0096] Preferably, the measuring device includes a battery and / or a rechargeable battery as an energy storage device, thus making the measuring device energy self-sufficient according to the invention. A battery and / or a rechargeable battery preferably provides sufficient energy for the communication unit to transmit the data.

[0097] In another embodiment, the battery or accumulator preferably supplies energy for the operation of the measuring device. In particular, the processing unit, the communication unit, and the sensor are simultaneously supplied with sufficient energy. Preferably, the measuring device includes an output for a charging port for recharging the accumulator.

[0098] In a further preferred embodiment, an integrated overcharge and discharge protection of the accumulator in the measuring device is included for the safe operation of the measuring device.

[0099] In another preferred embodiment, the accumulator is designed as a Li-ion or Li-Po battery. Furthermore, the measuring device can include an LED display.

[0100] In a further preferred embodiment, the measuring device is energy-independent from the tableting machine's power supply by generating its own induced current / induction. In a preferred configuration, an electrical conductor is located in the press ram, which moves within a magnetic field. The magnetic field can preferably be generated by a coil located inside and / or outside the rotor. The movement of the conductor induces a current, which is used to operate the measuring device.

[0101] In a preferred embodiment, the measuring device comprises a photovoltaic cell (solar cell) that also responds well to artificial light in machine halls. Based on the photoelectric effect, light energy is converted into electrical energy, and the measuring device can be operated energy-autonomously according to the invention. The generated electricity is preferably used directly for the measurement operation.

[0102] In another preferred embodiment, the generated electricity is stored in the aforementioned accumulators.

[0103] In a further preferred embodiment, the measuring device of one press die is connected to at least one second measuring device of a second press die. In a preferred variant, the connection is implemented via a signal conductor. In a further preferred embodiment of the invention, the connection is wireless via the communication unit. Power and / or data can preferably be transmitted via the connection of the measuring devices. Furthermore, all measuring devices can preferably be connected to a distribution unit.

[0104] In a preferred embodiment of the invention, the press punch is characterized in that the measuring device is integrated within the press punch body. According to the invention, the press punch body preferably comprises a press punch shaft, a press punch tip, and a press punch head, wherein the press punch body is preferably designed as a thick-walled hollow body or as a solid body. The advantage of an integrated measuring device is that the external geometry of the press punch remains unchanged, so that the geometric parameters of a tableting machine do not need to be altered due to the press punch.

[0105] In a further preferred embodiment, the measuring device is precisely fitted into a press die designed as a solid body. The press die is machined using separating manufacturing processes such that the measuring device can be inserted into the press die in a subsequent assembly process. Fastening elements can preferably also be used for this purpose. The measuring device can therefore preferably be materially bonded, force-fitted, and / or form-fitted within the press die.

[0106] In a preferred embodiment of the invention, the measuring device is mounted on the inner wall of the thick-walled hollow body of a press die. Preferably, access to the measuring device can be provided via a transverse bore to the longitudinal axis of the press die, in order to connect signal lines or route antennas.

[0107] In an exemplary embodiment, the measuring device is inserted into press dies with a shell diameter of 25.4 mm or into a press die with a shell diameter of 19 mm.

[0108] In preferred embodiments, the computing unit of the measuring device is connected to one or more data processing units and / or a programmable logic controller of a tableting machine.

[0109] In a preferred embodiment, a data processing unit is provided as a component designed externally from the tableting machine, which is designed as an independent device - separate from the tableting machine.

[0110] In another preferred embodiment, a data processing unit is provided as an internal data processing unit. An internal data processing unit can preferably be a component of the tableting machine and, for example, be integrated into the frame of a tableting machine. It is also preferably designed as a programmable logic controller (PLC) of the tableting machine and is preferably also referred to as a machine controller.

[0111] In preferred embodiments, the measuring device can communicate with one or more of the data processing units (e.g. external: PC, smartphone, tablet or internal: machine control).

[0112] Direct communication between the measuring device and the machine control system allows for rapid adjustment of the tableting machine's operating parameters based on the measurement results. For example, to prevent wear when predefined force limits are exceeded, the machine control system could adjust the operating parameters based on the transmitted information.

[0113] Preferably, however, the measuring device communicates with an (external) data processing unit, such as a PC, tablet computer, or smartphone. A data processing unit can therefore preferably also be designed as an external component (e.g., tablet computer, smartphone). Preferably, the external component communicates with both the measuring device and the machine control system.

[0114] For example, the (pre-processed) measurement results from the measuring unit can first be transmitted to a data processing unit in the form of a PC, tablet computer, etc., or to a computer program installed on it. Using the external components, a more comprehensive evaluation of the measurement results can be carried out, for example, for monitoring and / or logging the tableting process.

[0115] Based on the evaluation and verification by the staff, the operating parameters can then be adjusted, for example, by sending appropriate control commands to the machine control.

[0116] The ability to capture and record data from the measuring device on the data processing system offers several advantages, even independently of any adjustments to the operating parameters. Recording measurement data, in particular, ensures logging and thus quality assurance of the production process. For example, if predefined tolerance limits for the pressing forces are exceeded, the corresponding pressed products can be marked for further inspection. As explained above, recording measurement data also allows for the early detection of wear. Based on this information, repair or replacement of the respective components can be indicated, or the maintenance interval can be adjusted.

[0117] The invention further relates to a tableting machine comprising a press die of the type mentioned at the outset.

[0118] In a further preferred embodiment, the invention relates to a tableting machine comprising a programmable logic controller (PLC), wherein the PLC consists of at least one processing unit, one communication unit, and one storage unit, and wherein the measuring device of the press punch comprises a communication unit, characterized in that the communication unit of the PLC is compatible with the communication unit of the measuring device of the press punch. According to the invention, the communication unit of the PLC can be configured as a transmitting and / or receiving unit. The advantage of integrating the press punch according to the invention into the tableting machine is, in particular, the possibility of monitoring the tableting machine during operation and / or in standby mode.

[0119] For the purposes of the invention, compatibility of the communication units means that they are capable of communicating with each other. According to the invention, both communication units use the same data transmission methods mentioned above, so that data can be sent and received reciprocally.

[0120] In a further preferred embodiment, the tableting machine is designed as a rotary press or eccentric press. A rotary press preferably comprises a press ram of the type mentioned above, a rotor, a die disk, a ram guide for receiving press rams, a power supply, and upper and lower pressure rollers.

[0121] An eccentric press preferably comprises a press die of the type mentioned above, a die and a power supply.

[0122] In further preferred embodiments, a data processing unit, such as a smartphone or tablet computer, comprises a computing unit, a communication unit, and a storage unit. According to the invention, the communication unit of the data processing unit also serves to receive data from the communication unit of the measuring device and / or the programmable logic controller of the tablet machine (and / or to send data to these devices). The communication unit can receive / send data via a wired connection; however, wireless data transmission is particularly advantageous.

[0123] In a preferred embodiment, the communication unit of the data processing unit and / or programmable logic controller of the tableting machine preferably sends data for controlling the measuring device to the communication unit of the measuring device.

[0124] For example, the communication unit of the data processing unit and / or the programmable logic controller (PLC) of the tablet press can send control parameters to the measuring device for performing a measurement. These control parameters can relate to, for example, the type of measurement or the selection of active sensors (in the case of multiple sensors). They can also specify the measurement interval, a preferred transmission mode, or instructions for processing or pre-evaluating the raw data.

[0125] In a preferred embodiment, the communication unit of the measuring device sends data, preferably pre-processed measurement data, to the communication unit of the (external) data processing unit and / or the programmable logic controller of the tableting machine.

[0126] The data transmitted by the measuring device is preferably stored on the storage unit of the data processing unit and / or programmable logic controller (PLC) of the tablet press. According to the invention, the storage unit of the data processing unit and / or programmable logic controller of the tablet press preferably serves to back up or store data. Specifically, the measurement data acquired by the sensor is preferably stored in the storage unit. This applies both to the data obtained directly via the measuring device and to the analysis results of the data processing unit and / or programmable logic controller of the tablet press itself.Furthermore, software programs, as well as command sequences, mathematical and statistical models, are preferably also stored on the storage unit, which, as described, can be used to control the measuring device and / or to access (read) the data from the measuring device. The storage unit is preferably an electronic data carrier.

[0127] The computing unit of the data processing unit and / or programmable logic controller of the tablet machine preferably comprises a processor unit. The processor unit preferably comprises a graphics processing unit (GPU) and / or a central processing unit (CPU).

[0128] In a further preferred embodiment of the invention, at least one measuring device is attached to at least one arbitrary element of the tableting machine. Preferably, "arbitrary element" refers to a press punch, rotor, die disk, punch guide for receiving press punches, power supply, and an upper and lower pressure roller of a rotary press.

[0129] In a further preferred embodiment, the invention relates to a system comprising a data processing unit and a tableting machine of the type described above, wherein the measuring device of the press punch comprises a communication unit and the tableting machine comprises a programmable logic controller, characterized in that the data processing unit and / or the programmable logic controller of the tableting machine is configured to To receive and further process measured values ​​from the measuring device, preferably processed raw data, and / or to transmit control commands to the measuring device.

[0130] Such a system is advantageously suited for monitoring tableting processes because the measurement data can be processed (visualized and / or analyzed) on an external device with increased storage and computing capacity, whereas the measuring device itself can be kept very compact and requires only a few components. This means that data evaluation can preferably be performed online (immediately) without having to remove the measuring device or read the data manually. Furthermore, the measuring device advantageously records measurements directly at the die, enabling particularly precise and detailed statements about the pressing process. Additionally, the measuring device can receive control commands from users (or automatically) via external devices (data processing units or the tablet machine's programmable logic controller), allowing for the monitoring of specific parameters (e.g.,Sampling rates) can be performed from a remote position.

[0131] In a further preferred embodiment, the invention relates to a method for monitoring a tableting machine using a press punch of the type mentioned at the outset, wherein the measuring device of the press punch comprises a sensor, a computing unit, a communication unit and a storage unit, and the tableting machine comprises a programmable logic controller with a communication unit, characterized in that The sensor of the measuring device records physical and / or chemical properties; the measured values ​​recorded as raw data are processed by the computing unit of the measuring device; the processed measured values ​​are sent via the communication unit of the measuring device to the programmable logic controller of the tableting machine and / or data processing unit and / or the processed measured values ​​are saved on the storage unit of the measuring device.

[0132] The advantage of a method according to the invention is the possibility of monitoring and analyzing the condition of the tableting machine during the operating state and / or in the idle state.

[0133] In another preferred embodiment, the monitoring of the tableting machine preferably takes the form of technical monitoring. Such monitoring is designed, on the one hand, to prevent malfunctions and enable timely measures or repairs. On the other hand, it is an effective means of technical development and prevention of environmental damage.

[0134] In a preferred embodiment, the method is characterized in that the sensor of the measuring device in particular detects a force, temperature or acceleration of the press ram and / or its surroundings and / or the rotational speed of the rotor.

[0135] In another preferred embodiment, the recorded measured values ​​are saved in the storage unit of the data processing unit and / or in the storage unit of the programmable logic controller and / or in the storage unit of the measuring device.

[0136] In a further preferred embodiment, the method is characterized in that the programmable logic controller of the tablet machine and / or the data processing unit, preferably a tablet computer and / or a smartphone, can transmit control commands to the measuring device, preferably by means of a computer program product (application / app) installed on these devices.

[0137] In a further preferred embodiment of the invention, the secured measurement data are preferably analyzed by algorithms.

[0138] In a preferred embodiment of the invention, the storage unit of the measuring device is detachably mounted, so that a user of the machine can manually connect the data to be evaluated to a programmable logic controller of the tableting machine and / or the data processing unit.

[0139] In a further preferred embodiment of the invention, the computing unit of the data processing unit and / or the programmable logic controller directly accesses the measurement data stored in the storage unit of the data processing unit and / or in the storage unit of the programmable logic controller and executes the algorithms for analyzing the measurement data, which are also stored in the storage unit.

[0140] By analyzing the measurement data using algorithms, errors, wear and failures of a press die and / or other components of a tableting machine can be detected very early.

[0141] In a further preferred embodiment of the invention, the method is characterized in that the recorded measured values ​​of the measuring device are analyzed using machine learning algorithms.

[0142] In a further preferred embodiment, external parameters and / or measured values ​​from a press ram are incorporated into the analysis of the method for monitoring a tableting machine. These can be determined by measuring devices that are independent of the measuring device according to the invention. For example, in the case of rotary presses, recorded measurement data from the pressure roller (e.g., pressing forces), the rotor (e.g., revolutions), the die disk, or even, in a simple case, the ambient temperature of the tableting machine, can also be stored in a memory unit of the tableting machine's data processing unit and subsequently analyzed by downstream algorithms. A large number of differently recorded data points enables a comprehensive analysis with minimal errors.

[0143] In a further preferred embodiment, the method is characterized in that the recorded measured values ​​of the measuring device are analyzed in combination with externally recorded and / or provided measured values ​​using algorithms (preferably machine learning algorithms).

[0144] For the purposes of this invention, machine learning algorithms are a subfield of artificial intelligence. Machine learning uses mathematical and statistical models to "learn" from datasets. Generally, machine learning algorithms have the advantage that information too complex for a human observer can be automatically extracted from a large dataset. There are numerous machine learning algorithms, which can be broadly categorized into three different learning methods: supervised learning, unsupervised learning, and reinforcement learning.

[0145] In a preferred embodiment, supervised learning is used for the analysis or processing of the stored measurement data. In supervised learning, a training process is first performed. Here, training data in the form of input data is provided along with the corresponding target data. The purpose of training, generally in machine learning methods, is to adjust the parameters of a function so that the function is subsequently able to determine the target value from the corresponding input value with high accuracy. After the training process, the adjusted function is then used to predict target data for previously unseen input data. The function is described by a mathematical and / or statistical model.

[0146] In a preferred embodiment, the function is implemented using a support vector machine, Bayesian networks, and / or decision trees. Particularly preferably, the function is described by an artificial neural network. According to the invention, the artificial neural networks can have various architectures.

[0147] In accordance with the invention, the input data are preferably defined by machine parameters, environmental parameters, and / or measured data from the measuring device. Machine parameters preferably include rotor speed, various material properties and / or component characteristics, operating time, machine age, number of dies or other components, etc. Environmental parameters preferably include ambient temperature, humidity, etc.

[0148] Preferably, the measured data from various measuring devices, equipped with different sensors for measuring various physical and / or chemical properties, are used as input data.

[0149] According to the invention, target data are preferably defined by a probability of the occurrence of damage, the failure of a component or of an incorrect execution of a pressing process.

[0150] In another preferred embodiment, the unsupervised learning method is used for the analysis or processing of the stored measurement data. In unsupervised learning, the algorithm attempts to recognize patterns in the input data that deviate from structureless noise. The function in the training process focuses solely on the similarities of the input data and adjusts its parameters accordingly, so that no output data is used for the training process.

[0151] In a preferred embodiment, segmentation or clustering of the input data, or preferably compression of the input data, is performed using the unsupervised learning method.

[0152] In a preferred embodiment, the unsupervised learning algorithm preferably comprises principal component analysis (PCA) and / or the K-means algorithm and / or at least one neural network.

[0153] As already described, both of the methods mentioned above begin with so-called training processes to determine the optimal parameters of a machine learning function. Based on the adapted function, various predictions are then made for previously unknown input data.

[0154] In another preferred variant, the reinforcement learning method is used for the analysis or processing of the stored measurement data. In reinforcement learning, the training process continues even after the parameters of a function have been adjusted. Through trial and error, the effects of different statements are observed and evaluated using the adapted function and previously unknown input data. In response to these statements, the algorithm receives feedback, abstractly represented as a reward or punishment. The algorithm then further optimizes the function based on its parameters. Accordingly, the algorithm continuously adapts or modifies the function of the machine learning process. Reinforcement learning can preferably utilize the Q-learning method and / or the aforementioned methods.use neural networks and / or other neural networks as well as other algorithms known to experts.

Claims

1. A punch for a tableting machine wherein the punch has a measuring device which is energy self-sufficient and can function independently of a power supply to the tableting machine and wherein the measuring device comprises a sensor for recording physical and / or chemical properties characterized in that the measuring device is incorporated inside the punch body and comprises a communication unit, a memory unit, an energy storage unit and a computing unit, wherein the measured values obtained as raw data can be processed by means of the computing unit .

2. The punch according to one or more of the preceding claims characterized in that the sensor for recording physical and / or chemical properties is a sensor for recording a force, a temperature and / or an acceleration of the punch and / or its environment.

3. The punch according to one or more of the preceding claims characterized in that the tableting machine is a rotary tableting machine or eccentric tableting machine.

4. A tableting machine comprising a punch according to one or more of the preceding claims.

5. System comprising a. a tableting machine comprising a punch according to one or more of the preceding claims 1-3, b. a data processing unit, wherein the tableting machine comprises a programmable logic controller characterized in that the data processing unit and / or the programmable logic controller of the tableting machine are adapted to - receive and further process measured values, preferably processed raw data, from the measuring device and / or - transmit control commands to the measuring device.

6. A method of monitoring a tableting machine using a punch according to claims 1 to 3, - wherein the tableting machine comprises a programmable logic controller with a communication unit characterized in that - the measured values recorded as raw data are processed by the computing unit of the measuring device - the processed measured values are sent to the programmable logic controller of the tableting machine and / or data processing unit via the communication unit of the measuring device and / or the processed measured values are saved on the memory unit of the measuring device.

7. A method according to claim 6 characterized in that the sensor of the measuring device records a force, temperature or acceleration of the punch and / or its environment.

8. A method according to one or more of the preceding claims 6 - 7 characterized in that the programmable logic controller of the tableting machine and / or the data processing unit, preferably a tablet computer and / or a smartphone, can transmit control commands to the measuring device, preferably by means of a computer program product (application / app) installed on these devices.

9. A method according to one or more of the preceding claims 6 - 8 characterized in that the recorded measured values of the measuring device are analyzed.