Method and measurement chain for measuring a measurement variable in a manufacturing process step

Abstract

A method for measuring a measurement variable using a measurement chain having multiple measurement units and an analysis unit in a process step of a manufacturing process; each measurement unit having a sensor, a converter unit, and a sub-antenna; wherein the analysis unit has a main antenna; and wherein the following method steps are performed in each process step: positioning (I) one of the multiple measurement units at a measurement position for measuring the measurement variable; automatically coupling (II) the positioned measurement unit to the analysis unit by establishing a transmission connection between the sub-antenna and the main antenna; automatically generating (III) a measurement signal (MS) by the sensor of the positioned measurement unit under the action of the measurement variable; automatically converting (IV) the measurement signal into measurement data (MD) by the converter unit of the positioned measurement unit; and automatically transmitting (V) the measurement data to the main antenna by the sub-antenna of the positioned measurement unit.

Description

Technical Field

[0001] This invention relates to a method for measuring measurement variables during process steps in a manufacturing process, as described in the preamble of the first independent claim. The invention also relates to a measurement chain for performing this method. Background Technology

[0002] Typically, workpieces are machined using tools during the manufacturing process. Here, measured variables such as force, torque, bending moment, acceleration, and vibration act on the tool. To control the manufacturing process, it is desirable to know these measured variables. For this purpose, a measurement chain with multiple transmission components (e.g., sensors, signal lines, and analysis units) is used. Under the influence of the measured variable, the sensor generates a measurement signal, which is transmitted to the analysis unit via the signal lines. For accurate measurement of the measured variable, it is advantageous to mount the sensor as close to the tool as possible, where the measurement will not be distorted.

[0003] Such a measurement chain is known from document EP1323495A1. A rotating tool is equipped with a sensor device, which includes a sensor, an AD converter, and coil windings. The sensor detects the measurement variable acting on the rotating tool and generates a measurement signal for the detected variable. The AD converter digitizes the measurement signal into measurement data. Each sensor device is equipped with a fixed-position coil. The coil windings transmit the measurement data to the fixed-position coils using near-field telemetry. For this purpose, the coil windings and the fixed-position coils are arranged a few millimeters apart. Furthermore, the fixed-position coils also supply power to the sensor devices. Therefore, the sensor devices do not need to be independent. The fixed-position coils are connected to a main amplifier. The main amplifier analyzes the measurement data.

[0004] Document EP1323495A1 teaches the use of strain gauges as sensors. Compared to piezoelectric sensors, strain gauges have disadvantages in precision machining of workpieces, including limited measurement range and low dynamic measurement resolution. To achieve optimal resolution of the measurement signal, the measurement range in a strain gauge must be readjusted more frequently with changes in the magnitude of the measurement signal, which is costly. Furthermore, high dynamic measurement resolution up to 35 kHz is desired, especially for rapidly rotating workpieces.

[0005] Therefore, a mobile system is known from document WO2015176189A1, in which the measuring unit has a piezoelectric sensor, an electronic unit, and a mobile antenna. The electronic unit modulates the measurement signal from the piezoelectric sensor and / or compresses it into measurement data. The mobile antenna transmits the measurement data to a fixed antenna using far-field telemetry. Using far-field telemetry, the two antennas can be arranged several meters apart. To transmit the measurement data without interference, one of the two antennas is circularly polarized, while the other is linearly polarized. The fixed antenna is connected to a data processing unit that processes the measurement data. To supply power, the measuring unit has its own and / or its own energy generator.

[0006] The manufacturing process typically consists of multiple technological steps performed sequentially over time. Therefore, the workpiece is machined by a machine tool using different tools in multiple technological steps. Different tools are sequentially positioned on the workpiece and / or the workpiece is periodically positioned on new tools. That is, tools and / or workpieces are changed at each technological step.

[0007] According to the teachings of patent document EP1323495A1, the tool is replaced, and with the tool replacement, the sensor device and its fixed coil associated with the tool are also replaced. The sensor device and its fixed coil exist multiple times for each tool. This makes the purchase cost of the measurement chain very high. Furthermore, the measurement chain is interrupted each time the tool is replaced. To re-close the measurement chain, the sensor device and its fixed coil must be registered on the main amplifier.

[0008] Interruptions in the measurement chain are unavoidable. According to patent document WO2015176189A1, when the measurement unit and its moving antenna are replaced, the transmission connection for the fixed antenna is also interrupted. To close the measurement chain, the interrupted transmission connection between the two antennas must be re-established.

[0009] For a fast and cost-effective manufacturing process, the waiting time for the measurement chain to be interrupted during process steps should be as short as possible. Summary of the Invention

[0010] The first objective of this invention is to provide a method for measuring at least one measurement variable via a measurement chain in each process step of a manufacturing process comprising multiple process steps, wherein a measurement chain interrupted in a process step can be quickly re-closed. The second objective of this invention is to measure the measurement variable with high accuracy, high dynamic measurement resolution, and short latency.

[0011] Furthermore, a second objective of the present invention is to provide a measurement chain for performing the method, which is inexpensive to acquire and can be integrated into the machine tool used for the process step with minimal cost.

[0012] These two objectives are achieved through methods for measuring measurement variables in process steps of the manufacturing process and through measurement chains for performing said methods.

[0013] This invention relates to a method for measuring measurement variables using a measurement chain having multiple measurement units and an analysis unit in a process step of a manufacturing process performed using a machine tool; wherein each measurement unit has a sensor, a converter unit, and a secondary antenna; wherein the analysis unit has a main antenna; the machine tool is designed to process a workpiece sequentially in multiple process steps using multiple tools in a chronological order, for which a tool is positioned on the workpiece in each process step, and each tool is assigned a measurement unit; or the machine tool is designed to process multiple workpieces sequentially in a chronological order using a single tool in one process step, for which each workpiece is sequentially positioned on the tool in a chronological order, and each workpiece is assigned a measurement unit; or the machine tool is designed to process multiple workpieces sequentially in a chronological order using a single tool in one process step. One of multiple tools is used to process a workpiece, for which one tool is positioned on the workpiece, and each tool is assigned a measurement unit; and wherein the following method steps are performed in the process steps: by positioning the tool on the workpiece or positioning the workpiece on the tool, the measurement unit assigned to the positioned tool or the positioned workpiece is positioned at a measurement location for measuring the measurement variable; the positioned measurement unit and the analysis unit are automatically coupled by establishing a transmission connection between the sub-antenna and the main antenna; under the action of the measurement variable, a measurement signal is automatically generated by the sensor of the positioned measurement unit; the measurement signal is automatically converted into measurement data by the converter unit of the positioned measurement unit; and the measurement data is automatically transmitted to the main antenna by the sub-antenna of the positioned measurement unit.

[0014] The present invention also relates to a machine tool for performing the method, wherein each measuring unit positioned in the measuring position can be coupled to an analysis unit to establish a transmission connection between the sub-antenna and the main antenna.

[0015] In the method according to the invention, one of a plurality of measuring units is moved and positioned at a measuring location in each process step. At this measuring location, a measured variable is measured by the positioned measuring unit during the process step. However, moving the measuring unit and positioning it at the measuring location would cause the measurement chain between the measuring unit and the analysis unit to be interrupted. The measurement chain according to the invention can now be closed by coupling the positioned measuring unit to the analysis unit. Through this coupling, a transmission connection is established between the sub-antenna of the positioned measuring unit and the main antenna of the analysis unit. Through this coupling, the measurement chain is closed. This coupling is performed automatically. In the sense of the invention, the adjective "automatic" means that the establishment of the transmission connection is performed autonomously by the positioned measuring unit and the analysis unit without human intervention. Automatic coupling enables the measurement chain to be closed quickly.

[0016] Preferred embodiments of the present invention will be given below. Attached Figure Description

[0017] The present invention will now be described in detail by way of example with reference to the accompanying drawings.

[0018] Figure 1 A flowchart is shown of the method steps for measuring the measurement variable MG in the process steps of the manufacturing process.

[0019] Figure 2 It shows the method for execution Figure 1 A partial view of a first embodiment of the measurement chain 1 shown, which is a component of the first machine tool 3.

[0020] Figure 3 It shows according to Figure 2 A sectional view of a portion of the first machine tool 3;

[0021] Figure 4 It shows the method for execution Figure 1 A partial view of a second embodiment of the measurement chain 1 of the method shown, wherein the measurement chain 1 is a component of the second machine tool 4;

[0022] Figure 5 It shows according to Figure 4 A sectional view of a portion of the second machine tool 4;

[0023] Figure 6 It shows the method for execution Figure 1 A partial view of a third embodiment of the measurement chain 1 shown, wherein the measurement chain 1 is a component of the third machine tool 5; and

[0024] Figure 7 It shows according to Figure 6 A cross-sectional view of a portion of the third machine tool 5;

[0025] In the accompanying drawings, the same reference numerals denote the same objects.

[0026] The list of reference numerals in the attached figures is as follows:

[0027] 1 Measurement Chain

[0028] 2,2',2” workpiece

[0029] 3 First Machine Tool

[0030] 4 Second Machine Tool

[0031] 5. Third Machine Tool

[0032] 10, 10', 10” measurement units

[0033] 11, 11', 11” sensor

[0034] 12, 12', 12” converter unit

[0035] 13, 13', 13” Sub-antenna

[0036] 14", 14'", 14" Measurement signal cable

[0037] 15 Measurement Locations

[0038] 16, 16', 16" preload

[0039] 17, 17', 17” Subshell

[0040] 18, 18', 18" retainer

[0041] 19, 19', 19" Main interior space

[0042] 20 Analysis Units

[0043] 23 Main Antenna

[0044] 24 Measurement data lines

[0045] 25 Transmission distance

[0046] 27 Main housing

[0047] 29 Main Interior Space

[0048] 30 turret

[0049] 31, 31', 31” tool rack

[0050] 32, 32', 32” fasteners

[0051] 33, 33', 33” tools

[0052] 34, 34', 34” clamping parts

[0053] Leave 35, 35', 35" blank.

[0054] 40 bracket units

[0055] 41, 41', 41” tensioning unit

[0056] 42, 42', 42” tensioner

[0057] 43 tools

[0058] 44, 44', 44” clamping parts

[0059] Leave blanks at 45, 45', and 45".

[0060] 46 tensioning modules

[0061] 50 manipulators

[0062] 51, 51', 51” Replacement Head

[0063] 52, 52', 52" Coupler

[0064] 53, 53', 53” tools

[0065] 53.1, 53.2 Clamping arms

[0066] 53.1, 53.2 Magnets

[0067] 53.1 Vacuum Pump

[0068] 53.2 Suction Device

[0069] I. Positioning

[0070] II Automatic Coupling

[0071] III Automatic Generation

[0072] IV Automatic Conversion

[0073] V Automatic Transfer

[0074] BT preparation time

[0075] D12 is data specific to the converter unit.

[0076] ED unit data

[0077] EW Electromagnetic Alternating Field

[0078] ID identification code

[0079] KD calibration data

[0080] MG measurement variables

[0081] MD measurement data

[0082] MS measurement signal

[0083] SD serial number data

[0084] SR transmission rate

[0085] Z-axis Detailed Implementation

[0086] Figure 1 A flowchart illustrating the method steps for measuring a measurement variable MG during a process step in a manufacturing process is shown. The measurement variable MG is force, torque, bending moment, acceleration, vibration, etc.

[0087] To perform this method, a measurement chain 1 with multiple measurement units 10, 10', 10" and an analysis unit 20 is used. Figures 2 to 7 Three embodiments of the measurement chain 1 used to perform the method are partially illustrated. First, a general description of the measurement chain 1 is given. Then, partial details of each of these three embodiments of the measurement chain 1 are further described in detail.

[0088] Each of the plurality of measurement units 10, 10', 10" has a sensor 11, 11', 11"; a converter unit 12, 12', 12"; and an antenna 13, 13', 13"". For example, the plurality of measurement units 10, 10', 10" includes: a first measurement unit 10 having a first sensor 11, a first converter unit 12, and a first antenna 13; a second measurement unit 10' having a second sensor 11', a second converter unit 12', and a second antenna 13'; and a third measurement unit 10" having a third sensor 11"; a third converter unit 12"; and a third antenna 13".

[0089] Each of the plurality of measurement units 10, 10', 10" has a housing 17, 17', 17" in each housing. That is, there are a plurality of housings 17, 17', 17" in each housing. For example, the plurality of housings 17, 17', 17" includes: a first housing 17 having a first internal space 19 for the first converter unit 12 and the first sub-antenna 13; a second housing 17' having a second internal space 19' for the second converter unit 12' and the second sub-antenna 13'; and a third housing 17" having a third internal space 19" for the third converter unit 12" and the third sub-antenna 13". The plurality of housings 17, 17', 17" are made of mechanically resistant materials such as metal sheets or plastics.

[0090] Furthermore, the analysis unit 20 has a main housing 27 for the main antenna 23. The main housing 27 has a main internal space 29. The main antenna 23 is arranged in the main internal space 29. The main internal space 29 protects the main antenna 23 from harmful external influences, such as dirt, coolant, electromagnetic interference radiation, etc. The main housing 27 is also made of a mechanically resistant material such as metal sheet or plastic.

[0091] In the first method step, one of the plurality of measuring units 10, 10', 10" is positioned at a measuring position 15 for measuring the measurement variable MG. The measuring unit 10, 10', 10" is moved to the measuring position 15 and remains at the measuring position 15 during the process step.

[0092] In the second method step, by establishing a transmission connection between the sub-antennas 13, 13', 13” and the main antenna 23, the automatic coupling II of the positioned measurement units 10, 10', 10” and the analysis unit 20 is realized.

[0093] To couple the positioned measurement units 10, 10', 10" with the analysis unit 20, the main antenna 23 generates and transmits an electromagnetic alternating field EW. The electromagnetic alternating field EW... Figure 3 and Figure 5 The electromagnetic alternating field EW is shown as a curved circular segment. Preferably, the electromagnetic alternating field EW has a frequency of 125 kHz. The effective range of the electromagnetic alternating field EW is limited so that only the sub-antennas 13, 13', 13" of the measurement units 10, 10', 10" which are fully positioned at the measurement location 15 can receive the electromagnetic alternating field EW.

[0094] Once and as soon as the secondary antennas 13, 13', 13" receive the electromagnetic alternating field EW, power is supplied to the measurement units 10, 10', 10" . The secondary antennas 13, 13', 13" are preferably induction coils with multiple windings and a capacitor. The electromagnetic alternating field EW induces a voltage in the induction coil, which charges the capacitor with electrical energy. This electrical energy is used for the operation of the measurement units 10, 10', 10" . While the capacitor is being charged, the measurement units 10, 10', 10" are supplied with sufficient electrical energy for their operation. Preferably, the charging of the capacitor is performed within a 100ms operation preparation time BT, more preferably within a 20ms operation preparation time BT.

[0095] Upon reaching the operational readiness state of measurement units 10, 10', and 10" respectively, the secondary antennas 13, 13', and 13" establish a transmission connection to the main antenna 23. Preferably, the transmission connection to the main antenna 23 is established immediately upon reaching the operational readiness state of measurement units 10, 10', and 10" respectively. To establish the transmission connection to the main antenna 23, the secondary antennas 13, 13', and 13" transmit an identification code ID to the main antenna 23. The identification code ID is stored in the data memory of measurement units 10, 10', and 10" respectively. Preferably, the data memory is arranged in the converter units 12, 12', and 12" respectively. The identification code ID uniquely identifies measurement units 10, 10', and 10" respectively. The main antenna 23 receives the identification code ID. The transmission of the identification code ID is... Figure 3 and Figure 5 The middle section is shown as a curved circular segment. The main antenna 23 transmits the identification code ID to the analysis unit 20. The analysis unit 20 identifies the measurement units 10, 10', and 10'" based on the received and transmitted identification code ID. By receiving the identification code ID and identifying the measurement units 10, 10', and 10'", the coupling II between the located measurement units 10, 10', and 10'" and the analysis unit 20 is completed.

[0096] In the third method step, under the action of the measured variable MG, the measurement signal MS is automatically generated by the sensors 11, 11', 11" of the positioned measurement units 10, 10', 10" Ⅲ.

[0097] Sensors 11, 11', and 11" are configured to detect the measured variable MG and generate a measurement signal MS for the detected measured variable MG. Sensors 11, 11', and 11" detect and generate the measurement signal MS every unit time. The unit time can be 1 millisecond (ms), 100 microseconds (100 μs), etc. The reciprocal of the unit time is the dynamic measurement resolution. Therefore, the time series of measurement signals MS generated by sensors 11, 11', and 11" is represented, where each measurement signal MS has a magnitude and a time point.

[0098] Sensors 11, 11', 11" can be piezoelectric sensors, piezoresistive sensors, strain gauges, etc. Each sensor 11, 11', 11" has signal cables 14, 14', 14". The signal cables 14, 14', 14" are configured to transmit the measurement signal MS to the converter units 12, 12', 12".

[0099] Preferably, sensors 11, 11', and 11" are piezoelectric sensors. The piezoelectric sensors utilize piezoelectric materials such as quartz or piezoelectric ceramics. The measured variable MG acts as a tensile and / or compressive load on the piezoelectric material. Under the action of the measured variable MG, the piezoelectric material generates a measurement signal MS in the form of electrical charge. The amount of charge is proportional to the value of the measured variable MG. Figure 3 , Figure 5 and Figure 7 The piezoelectric sensor is mechanically pre-tightened by a pre-tightening element 16, 16', 16” such as a screw or sleeve. Through this mechanical pre-tightening, the piezoelectric material can detect tensile and compressive loads. The piezoelectric sensor is characterized by a high dynamic measurement resolution up to 35 kHz.

[0100] In the fourth method step, the converter units 12, 12', 12" of the positioned measurement units 10, 10', 10" perform automatic conversion IV from measurement signal MS to measurement data MD.

[0101] Converter units 12, 12', 12" are configured to digitize the measurement signal MS into measurement data MD. Preferably, the converter units 12, 12', 12" for the piezoelectric sensor have a charge amplifier. This charge amplifier amplifies the charge of the piezoelectric sensor and converts it into a voltage. The converter units 12, 12', 12" digitize this voltage into measurement data MD. The magnitude and time point of the measurement signal MS are converted and digitized into the magnitude and time point of the measurement data MD.

[0102] Preferably, converter units 12, 12', 12" are configured to generate unit data ED, which represents the unit of the measured variable MG, which has been converted and digitized into measured data MD by converter units 12, 12', 12" from the measured signal MS. For example, the force of the measured variable MG has a unit Newton (N), the torque or bending moment of the measured variable MG has a unit Newton-meter (Nm), and the acceleration or vibration of the measured variable MG has a unit gravitational acceleration (g).

[0103] Preferably, the converter units 12, 12', 12" are configured to read the calibration data KD of sensors 11, 11', 11" from the data memory of the measurement units 10, 10', 10" where sensors 11, 11', 11" have generated a measurement signal MS under the action of the measurement variable MG. The calibration data KD represents the temperature-related sensitivity of sensors 11, 11', 11" at that temperature, where sensors 11, 11', 11" have generated the measurement signal MS. For piezoelectric sensors, the calibration data KD can also represent the sensitivity of sensors 11, 11', 11" related to the magnitude of the mechanical preload, where sensors 11, 11', 11" have generated the measurement signal MS using that mechanical preload.

[0104] Preferably, converter units 12, 12', 12" are configured to read serial number data SD of converter units 12, 12', 12" from the data memory of measurement units 10, 10', 10" . The serial number data SD uniquely identifies converter units 12, 12', 12" which convert and digitize the measurement signal MS into measurement data MD.

[0105] Furthermore, in the fifth method step, the sub-antennas 13, 13', and 13" of the positioned measurement units 10, 10', and 10" perform the automatic transmission of measurement data MD to the main antenna 23.

[0106] Sub-antennas 13, 13', and 13" are configured to transmit measurement data MD to the main antenna 23. The sub-antennas 13, 13', and 13" preferably transmit the measurement data MD to the main antenna 23 at a carrier frequency of 13.56 MHz and a high transmission rate SR up to 1.6 Mbit / s. Therefore, sensors 11, 11', and 11" can measure the measurement variable MG with a high dynamic range resolution up to 35 kHz, and the sub-antennas 13, 13', and 13" can transmit the measurement data MD to the main antenna 23 at a resolution up to 24 bits and a transmission rate SR up to 1.6 Mbit / s.

[0107] Preferably, the sub-antennas 13, 13', 13" are configured to transmit unit data ED, calibration data KD, and serial number data SD together with measurement data MD to the main antenna 23.

[0108] Preferably, the analysis unit 20 has a data memory containing converter-specific data D12. For converter units 12, 12', 12'" of measurement chain 1, the converter-specific data D12 includes the time constant of converter units 12, 12', 12'", noise of converter units 12, 12', 12'", etc. The analysis unit 20 is configured to assign the sequence number data SD transmitted along with the measurement data MD and the converter-specific data D12 to converter units 12, 12', 12'" that have already converted and digitized the measurement signal MS into measurement data MD. The analysis unit 20 reads the assigned converter-specific data D12 from the data memory.

[0109] Analysis unit 20 is configured to analyze measurement data MD. For example, analysis unit 20 graphically represents measurement data MD as a time series, with the vertical axis representing the magnitude of measurement data MD and the horizontal axis representing the time points of measurement data MD. When analyzing measurement data MD, analysis unit 20 considers unit data ED, calibration data KD, and converter unit-specific data D12. Preferably, analysis unit 20 graphically represents unit data ED. Preferably, analysis unit 20 calibrates measurement data MD using calibration data KD and converter unit-specific data D12. For example, analysis unit 20 multiplies the magnitude of a single measurement data MD by the temperature-dependent sensitivity of sensors 11, 11', 11" and / or by the mechanical preload-dependent sensitivity of sensors 11, 11', 11" . For example, analysis unit 20 filters measurement data MD using the time constants of converter units 12, 12', 12" and / or graphically records the noise of converter units 12, 12', 12" as error bars (Fehlerbalken). All these measures improved the measurement accuracy of the variable MG.

[0110] First implementation method

[0111] According to Figure 2 In the first embodiment, the measuring chain 1 is a component of the first machine tool 3 (e.g., a lathe, turret lathe, etc.). Figure 3 Details of the first machine tool 3 are shown. Preferably, the first machine tool 3 is a turret lathe, which includes a turret 30 and a plurality of tool holders 31, 31', 31" arranged on the turret 30. The tool holders 31, 31', 31" are replaceably fastened to the turret 30. Preferably, the tool holders 31, 31', 31" are fastened to the turret 30 by fasteners 32, 32', 32" (e.g., screws, bolts, etc.). The turret 30, the tool holders 31, 31', 31" and the fasteners 32, 32', 32" are made of mechanically resistant materials such as steel or tool steel.

[0112] Each tool holder 31, 31', 31" stores tools 33, 33', 33". Tools 33, 33', 33" are also made of mechanically resistant materials such as steel or tool steel. Preferably, tools 33, 33', 33" are clamped in tool holders 32, 32', 32" by clamping elements 34, 34', 34" (e.g., screws, pins, etc.). Tools 33, 33', 33" have cutting wedges (Schneidkeil) made of hard, strong, and tough cutting materials (e.g., metal, ceramic, etc.). Figure 2The illustration shows, for example, three tool racks 31, 31', 31" and three tools 33, 33', 33". The three tool racks 31, 31', 31" and the three tools 33, 33', 33" include a first tool rack 31 for storing the first tool 33, a second tool rack 31' for storing the second tool 33' and a third tool rack 31 for storing the third tool 33".

[0113] The turret 30 is movably mounted on the first machine tool 3. The turret 30 can rotate about the longitudinal axis Z on the first machine tool 3. Figure 2 The image is shown with a curved double arrow. By rotating the turret 30 around the longitudinal axis Z, tools 33, 33', and 33" can be sequentially positioned on workpiece 2 in chronological order. Workpiece 2 is made of any material, such as metal, plastic, or glass. Workpiece 2 is processed sequentially by tools 33, 33', and 33" in multiple process steps. For each process step, a tool 33, 33', or 33" is positioned on workpiece 2, and the positioned tool 33, 33', or 33" performs cutting operations on workpiece 2. Figure 2 For example, the first tool 33 is positioned on the workpiece 2. During the cutting process, the measurement variable MG to be measured is applied to the positioned tools 33, 33', and 33" . Preferably, the replacement of tools 33, 33', and 33" on the workpiece 2 is performed within a 500ms preparation time.

[0114] Each tool rack 31, 31', 31" is assigned a measuring unit 10, 10', 10" according to Figure 2 For example, three tool holders 31, 31', 31" and three measurement units 10, 10', 10" are shown. These three measurement units 10, 10', 10" include a first measurement unit 10 of the first tool holder 31, a second measurement unit 10' of the second tool holder 31', and a third measurement unit 10 of the third tool holder 31". Each measurement unit 10, 10', 10" has sensors 11, 11', 11"; a converter unit 12, 12', 12"; and a sub-antenna 13, 13', 13".

[0115] according to Figure 3Each tool holder 31, 31', 31" has an aussparung 35, 35', 35". Sensors 11, 11', 11" of the measuring units 10, 10', 10" assigned to the tool holders 31, 31', 31" are arranged within this aussparung 35, 35', 35". Preferably, the aussparung 35, 35', 35" is located inside the tool holders 31, 31', 31" and the sensors 11, 11', 11" are completely arranged within the aussparung 35, 35', 35". The aussparung 35, 35', 35" protects the sensors 11, 11', 11" from harmful external influences such as dirt, coolant, and electromagnetic radiation. Tool racks 31, 31', and 31" have through-holes that guide signal cables 14, 14', and 14" from open spaces 35, 35', and 35" to outside tool racks 31, 31', and 31". These through-holes are waterproof.

[0116] Preferably, the sub-housing housings 17, 17', and 17" are arranged on the turret 30. The sub-housing housings 17, 17', and 17" are fixed to the turret 30 by retainers 18, 18', and 18" such as screws or bolts. The sub-housing housings 17, 17', and 17" are arranged spatially spaced from the sensors 11, 11', and 11" respectively. Preferably, the sub-housing housings 17, 17', and 17" are arranged at a constant spatial distance of less than or equal to 10 cm from the sensors 11, 11', and 11" respectively.

[0117] To replace the tool holders 31, 31', 31" on the turret 30, the tool holders 31, 31', 31" are replaced together with the measuring units 10, 10', 10" assigned to them. To do this, the tool holders 31, 31', 31" to be replaced are removed from the turret 30 by loosening their fasteners 32, 32', 32" and the sub-housings 17, 17', 17" connected to them via signal cables 14, 14', 14" are removed from the turret 30 by loosening their retainers 18, 18', 18" Subsequently, the new tool holders 31, 31', 31” are secured to the turret 30 by their fasteners 32, 32', 32”, while the sub-housings 17, 17', 17” connected to them via signal cables 14, 14', 14” are secured to the turret 30 by their retainers 18, 18', 18”. The replacement of the tool holders 31, 31', 31” with the measurement units 10, 10', 10” assigned to them is quick and easy.

[0118] according to Figure 2 For example, the first measuring unit 10 is positioned at the measuring position 15, and the first sensor 11 of the first measuring unit 10 detects the measuring variable MG acting on the first tool 33.

[0119] When sensors 11, 11', 11" and sub-housings 17, 17', 17" are movably arranged on the first machine tool 3, they are able to rotate about the longitudinal axis Z on the turret 30, while the main housing 27 is fixedly arranged on the first machine tool 3. Preferably, the main housing 27 is fixed to the turret 30 by fasteners (e.g., bolts, screws, etc.) not shown. The sub-housings 17, 17', 17" and the main housing 27 are movable relative to each other.

[0120] The first machine tool 3 is configured such that the sub-housings 17, 17', 17" of the measuring units 10, 10', 10" positioned at the measuring position 15 are located at a transmission distance 25 from the main housing 27. Preferably, the transmission distance 25 between the sub-housings 17, 17', 17" of the measuring units 10, 10', 10" positioned at the measuring position 15 and the main housing 27 is equal to the range of action of the electromagnetic alternating field EW.

[0121] Second implementation method

[0122] According to Figure 4 In the second embodiment, the measuring chain 1 is a component of the second machine tool 4 (e.g., a tensioning system, a zero-point tensioning system, etc.). Figure 5 Details of the second machine tool 4 are shown. Preferably, the second machine tool 4 is a zero-point tensioning system having a support unit 40 and a plurality of tensioning units 41, 41', 41"". Each of the plurality of tensioning units 41, 41', 41" is replaceably fastened to the support unit 40. In this zero-point tensioning system, the tensioning units 41, 41', 41" can be replaced without zero-point loss.

[0123] Preferably, the plurality of tensioning units 41, 41', 41" are fastened to the tensioning module 46 of the support unit 40 by tensioning elements 42, 42', 42" such as pins or bolts. For example, according to Figure 4 Each of the multiple tensioning units 41, 41', 41" has four tensioning elements 42, 42', 42" which can be fastened into the four tensioning modules 46 of the support unit 40. After the tensioning elements 42, 42', 42" are inserted into the tensioning modules 46, they are secured in the tensioning modules 46 by form-fitting mechanisms, for example, spring force. The loosening of this fastening is pneumatic. Replacement of the tensioning units 41, 41', 41" is preferably performed within a 500ms preparation time. The support unit 40, tensioning units 41, 41', 41" and tensioning elements 42, 42', 42" and tensioning modules 46 are made of mechanically resistant materials such as steel and tool steel.

[0124] Each of the plurality of tensioning units 41, 41', 41" houses one workpiece 2, 2', 2". Workpieces 2, 2', 2" are made of any material, such as metal, plastic, or glass. Preferably, workpieces 2, 2', 2" are clamped in the tensioning units 41, 41', 41" by clamping elements 44, 44', 44" (e.g., vises, jigs, etc.). Figure 4 For example, three tensioning units 41, 41', 41" and three workpieces 2, 2', 2" are shown. The three tensioning units 41, 41', 41" and the three workpieces 2, 2', 2" include a first tensioning unit 41 that houses the first workpiece 2, a second tensioning unit 41' that houses the second workpiece 2', and a third tensioning unit 41 that houses the third workpiece 2".

[0125] That is, there are multiple workpieces 2, 2', 2'". The second machine tool 4 is configured to process each of the multiple workpieces 2, 2', 2'" in one process step using tool 43. To this end, the workpieces 2, 2', 2'" housed in the tensioning units 41, 41', 41'" are sequentially positioned on tool 43 of the second machine tool 4 in chronological order, and each positioned workpiece 2, 2', 2'" is machined by tool 43. Figure 5 Tool 43 has a cutting wedge made of a hard, strong, and tough cutting material (such as metal, ceramic, etc.). During the cutting process, the measurement variable MG to be measured acts on the positioned workpieces 2, 2', 2" .

[0126] Measuring units 10, 10', and 10" are provided on each of the multiple tensioning units 41, 41', and 41" respectively. Figure 4 For example, three tensioning units 41, 41', 41" and three measuring units 10, 10', 10" are shown. The three measuring units 10, 10', 10" include a first measuring unit 10 assigned to the first tensioning unit 41, a second measuring unit 10' assigned to the second tensioning unit 41', and a third measuring unit 10 assigned to the third tensioning unit 41".

[0127] according to Figure 5 Measurement units 10, 10', 10” are positioned at measurement position 15, and sensors 11, 11', 11” of measurement units 10, 10', 10” detect the measurement variable MG acting on workpieces 2, 2', 2”.

[0128] Preferably, measuring units 10, 10', 10” are clamped together with workpieces 2, 2', 2” in clamping members 44, 44', 44”. Sensors 11, 11', 11” are clamped spatially close to workpieces 2, 2', 2” in open spaces 45, 45', 45”. Figure 5Sensors 11, 11', 11" are clamped in direct mechanical contact with workpieces 2, 2', 2".

[0129] Preferably, the sub-housing housings 17, 17', and 17" are arranged on the tensioning units 41, 41', and 41" respectively. Preferably, the sub-housing housings 17, 17', and 17" are partially identical to the housings of the tensioning units 41, 41', and 41" respectively. The sub-housing housings 17, 17', and 17" are arranged spatially spaced from the sensors 11, 11', and 11" respectively. Preferably, the sub-housing housings 17, 17', and 17" are arranged at a constant spatial distance of less than or equal to 10 cm from the sensors 11, 11', and 11" respectively.

[0130] To replace workpieces 2, 2', 2" in tensioning units 41, 41', 41" and clamping members 44, 44', 44" can be detached from the workpieces 2, 2', 2" to be replaced and reconnected to the replacement workpieces 2, 2', 2". Preferably, sensors 11, 11', 11" are retained in vacancy 45, 45', 45" during the replacement process. Only workpieces 2, 2', 2" are replaced. The establishment and detachment of clamping workpieces 2, 2', 2" and sensors 11, 11', 11" are simple and quick. This allows workpieces 2, 2', 2" to be replaced, while sensors 11, 11', 11" and sub-housing units 12, 12', 12" and sub-antennas 13, 13', 13" remain on tensioning units 41, 41', 41".

[0131] When sensors 11, 11', 11" and sub-housings 17, 17', 17" are movably arranged on the second machine tool 4, they can be replaceably fastened to the support unit 40 together with tensioning units 41, 41', 41" while the main housing 27 is fixedly arranged on the second machine tool 4. Preferably, the main housing 27 is partially identical to the housing of the support unit 40. Sub-housings 17, 17', 17" and the main housing 27 are movable relative to each other.

[0132] The second machine tool 4 is configured such that the sub-housing units 10, 10', 10" of the measuring units 10, 10', 10" positioned at the measuring position 15 are located at a transmission distance 25 from the main housing 27. Preferably, the transmission distance 25 is less than or equal to 10 mm. Preferably, the transmission distance 25 between the sub-housing units 17, 17', 17" of the measuring units 10, 10', 10" positioned at the measuring position 15 and the main housing 27 is equal to the range of action of the electromagnetic alternating field EW.

[0133] Third implementation method

[0134] According to Figure 6In the third embodiment, the measuring chain 1 is a component of the third machine tool 5 (e.g., an industrial robot, an industrial robot with a replacement head, etc.). Figure 7 Details of the third machine tool 5 are shown. Preferably, the third machine tool 5 is an industrial robot having a manipulator 50 and multiple replacement heads 51, 51', 51"". Each of the multiple replacement heads 51, 51" is replaceably fastened to the manipulator 50. Preferably, the replacement heads 51, 51', 51" are fastened to the manipulator 50 by couplings 52, 52', 52" (e.g., pluggable connectors, media couplers, etc.). Preferably, the replacement of the replacement heads 51, 51', 51" on the manipulator 50 is performed within a 500ms preparation time. The manipulator 50, the replacement heads 51, 51', 51" and the couplings 52, 52', 52" are made of mechanically resistant materials such as steel and tool steel.

[0135] Each of the multiple replacement heads 51, 51', 51" in the storage tool 53, 53', 53" is based on Figure 6 The illustration shows, for example, three replacement heads 51, 51', 51" with three tools 53, 53', 53" respectively. The three replacement heads 51, 51', 51" and the three tools 51, 51', 51" include a first replacement head 51 that houses the first tool 53, a second replacement head 51' that houses the second tool 53', and a third replacement head 51 that houses the third tool 53".

[0136] In the implementation of the parallel gripper, the first tool 53 has two gripping arms 53.1 and 53.2, between which a clamping force can be applied. This clamping force is a measured variable MG.

[0137] In one embodiment of the magnetic gripper, the second tool 53' has two magnets 53.1' and 53.2', between which a magnetic attraction force can be applied. This magnetic attraction force is a measured variable MG.

[0138] In an embodiment of the suction gripper, the third tool 53” has a vacuum pump 53.1” and a suction device 53.2”, the vacuum pump 53.1” being able to generate a vacuum, and the suction device 53.2” being able to apply a suction force due to the vacuum. This suction force is a measured variable MG.

[0139] The third machine tool 5 is configured to process a workpiece 2 in a process step. This processing is arbitrary and can include holding, transporting, machining, etc. According to... Figure 6 and Figure 7In the example, the first tool 53 uses clamping arms 53.1 and 53.2 to clamp the egg-shaped workpiece 2. To do this, the first tool 53 applies a clamping force acting between the clamping arms 53.1 and 53.2 onto the workpiece 2. Through this clamping force, the workpiece 2 is held by the first tool 53 and can be processed.

[0140] A measuring unit 10, 10', 10" is arranged on each of the multiple replacement heads 51, 51', 51" according to Figure 6 For example, three replacement heads 51, 51', 51" and three measuring units 10, 10', 10" are shown. The three measuring units 10, 10', 10" include a first measuring unit 10 assigned to the first replacement head 51, a second measuring unit 10' assigned to the second replacement head 51', and a third measuring unit 10 assigned to the third replacement head 51".

[0141] Therefore, according to Figure 6 and Figure 7 The first measuring unit 10 is positioned at the measuring position 15, and the first sensor 11 of the first measuring unit 10 detects the clamping force acting on the first tool 53 as the measuring variable MG.

[0142] according to Figure 7 The first replacement head 51 has an opening 35. A first sensor 11 of the first measuring unit 10 assigned to the first replacement head 51 is arranged in this opening 35. Preferably, the opening 35 is located inside the first replacement head 51, and the first sensor 11 is completely arranged within the opening 35. The opening 35 protects the first sensor 11 from harmful external influences, such as dirt, coolant, electromagnetic radiation, etc. The first replacement head 51 has a through-hole that guides the signal cable 14 from the opening 35 to the outside of the replacement head 51. This through-hole is waterproof.

[0143] Preferably, the first secondary housing 17 is disposed on the first replacement head 51. The first secondary housing 17 is fixed to the first replacement head 51 by a retaining element (e.g., screw, bolt, etc.) not shown. The first secondary housing 17 is disposed spaced apart from the first sensor 11. Preferably, the first secondary housing 17 is disposed at a constant spatial distance of less than or equal to 10 cm from the first sensor 11.

[0144] When sensors 11, 11', 11" and sub-housings 17, 17', 17" are movably arranged on the third machine tool 5, they are replaceably fastened to the manipulator 50 by tool heads 51, 51', 51" while the main housing 27 is fixedly arranged on the third machine tool 5. Preferably, the main housing 27 is fixed to the manipulator 50 by retaining elements (e.g., screws, bolts, etc.) not shown. Sub-housings 17, 17', 17" and the main housing 27 are movable relative to each other.

[0145] The third machine tool 5 is configured such that the sub-housing units 10, 10', 10" of the measuring units 10, 10', 10" positioned at the measuring position 15 are located at a transmission distance 25 from the main housing 27. Preferably, the transmission distance 25 is less than or equal to 10 mm. Preferably, the transmission distance 25 between the sub-housing units 17, 17', 17" of the measuring units 10, 10', 10" positioned at the measuring position 15 and the main housing 27 is equal to the range of action of the electromagnetic alternating field EW.

Claims

1. A method for measuring a measurement variable using a measurement chain, the measurement chain comprising an analysis unit and a plurality of measurement units, the measurement variable occurring in a process step of a manufacturing process and generated by the interaction between a machine tool and a workpiece during the manufacturing process; wherein, The analysis unit has a main antenna; wherein each of the plurality of measurement units includes a sensor and a sub-housing with a converter unit and a sub-antenna, the sensor having a signal cable for transmitting measurement signals to the converter unit; The machine tool is a turret lathe, which is configured to rotate around a longitudinal axis. The turret has multiple tool racks; The plurality of tool racks are arranged on the turret and configured to rotate together with the turret about the longitudinal axis; Each of the plurality of tool racks is configured to hold a tool; Each of the plurality of measuring units is assigned to one of the plurality of tool racks; The sensor of one of the plurality of measuring units, which is assigned to one of the plurality of tool racks, is arranged in the empty space of the tool rack to which the measuring unit is assigned. The sub-housing housing, which is assigned to one of the plurality of measurement units in one of the plurality of tool racks and has a converter unit and a sub-antenna, is arranged on the turret. The signal cable of the sensor of one of the plurality of measuring units assigned to one of the plurality of tool holders extends from the open space of the tool holder and connects to the sub-housing of the converter unit of the measuring unit assigned to the tool holder; and The turret is configured such that its rotation around the longitudinal axis facilitates the sequential positioning of the tool on the workpiece in chronological order. The method includes the following steps: The workpiece and the machine tool are arranged relative to each other, such that the measuring unit is positioned at a measuring location for measuring the measured variable; A transmission connection is established between the corresponding sub-antenna of the corresponding measurement unit and the main antenna so as to automatically couple the corresponding located measurement unit with the analysis unit. Use the corresponding sensor of the corresponding positioned measuring unit to automatically generate a measurement signal; Using the corresponding converter unit of the corresponding positioned measurement unit, the measurement signal is automatically converted into measurement data; and The measurement data is automatically transmitted to the main antenna via the corresponding secondary antenna of the corresponding positioned measurement unit.

2. A method for measuring a measurement variable using a measurement chain, the measurement chain comprising an analysis unit and a plurality of measurement units, the measurement variable occurring in a process step of a manufacturing process and generated by the interaction between a machine tool and a workpiece during the manufacturing process; wherein, The analysis unit has a main antenna; wherein each of the plurality of measurement units includes a sensor and a sub-housing with a converter unit and a sub-antenna, the sensor having a signal cable for transmitting measurement signals to the converter unit; The machine tool has a support unit and multiple tensioning units. Each of the plurality of tensioning units is replaceably fastened to the support unit; Each of the plurality of tensioning units is configured to house a workpiece; Each of the plurality of measuring units is assigned to one of the plurality of tensioning units; The sensor of one of the plurality of measuring units, which is assigned to one of the plurality of tensioning units, is arranged on the tensioning unit to which the measuring unit is assigned. The sub-housing housing, which is assigned to one of the plurality of tensioning units and one of the plurality of measuring units, and has a converter unit and a sub-antenna, is arranged on the tensioning unit; The signal cable of the sensor of one of the plurality of measuring units, which is assigned to one of the plurality of tensioning units, is guided to the sub-housing housing where the converter unit of the measuring unit assigned to that tensioning unit is located. The method includes the following steps: The workpiece and the machine tool are arranged relative to each other, such that the measuring unit is positioned at a measuring location for measuring the measured variable; A transmission connection is established between the corresponding sub-antenna of the corresponding measurement unit and the main antenna so as to automatically couple the corresponding located measurement unit with the analysis unit. Use the corresponding sensor of the corresponding positioned measuring unit to automatically generate a measurement signal; Using the corresponding converter unit of the corresponding positioned measurement unit, the measurement signal is automatically converted into measurement data; and The measurement data is automatically transmitted to the main antenna via the corresponding secondary antenna of the corresponding positioned measurement unit.

3. A method for measuring a measurement variable using a measurement chain, the measurement chain comprising an analysis unit and a plurality of measurement units, the measurement variable occurring in a process step of a manufacturing process and generated by the interaction between a machine tool and a workpiece during the manufacturing process; wherein, The analysis unit has a main antenna; wherein each of the plurality of measurement units includes a sensor and a sub-housing with a converter unit and a sub-antenna, the sensor having a signal cable for transmitting measurement signals to the converter unit; The machine tool is an industrial robot with a manipulator and multiple replacement heads; Each of the plurality of replacement heads is replaceably fastened to the manipulator; Each of the plurality of replacement heads is configured to accommodate a workpiece; Each of the plurality of measuring units is assigned to one of the plurality of replacement heads; The sensor of one of the plurality of measuring units, which is assigned to one of the plurality of replacement heads, is arranged on the replacement head to which the measuring unit is assigned. The sub-housing housing, which is assigned to one of the plurality of measurement units of the plurality of replacement heads and has a converter unit and a sub-antenna, is arranged on the manipulator. The signal cable of the sensor of one of the plurality of measuring units, which is assigned to one of the plurality of tensioning units, is guided to the sub-housing of the converter unit of the measuring unit assigned to the replacement head. The method includes the following steps: The workpiece and the machine tool are arranged relative to each other, such that the measuring unit is positioned at a measuring location for measuring the measured variable; A transmission connection is established between the corresponding sub-antenna of the corresponding measurement unit and the main antenna so as to automatically couple the corresponding located measurement unit with the analysis unit. Use the corresponding sensor of the corresponding positioned measuring unit to automatically generate a measurement signal; Using the corresponding converter unit of the corresponding positioned measurement unit, the measurement signal is automatically converted into measurement data; and The measurement data is automatically transmitted to the main antenna via the corresponding secondary antenna of the corresponding positioned measurement unit.

4. The method according to any one of claims 1 to 3, characterized in that, Each measurement unit positioned at the measurement location can be coupled to the analysis unit to establish a transmission connection between the secondary antenna and the primary antenna.

5. The method according to claim 4, characterized in that, The main antenna generates and transmits an electromagnetic alternating field; the effective range of the electromagnetic alternating field is limited so that only the measuring unit completely positioned at the measuring location can receive the electromagnetic alternating field.

6. The method according to claim 5, characterized in that, Once and as soon as the sub-antenna receives the electromagnetic alternating field, power is supplied to the measurement unit; and sufficient power is supplied to the measurement unit for operation within a 100 ms operation preparation time, preferably within a 20 ms operation preparation time.

7. The method according to claim 6, characterized in that, When the measurement unit reaches the operational readiness state, the secondary antenna establishes a transmission connection to the main antenna, wherein the secondary antenna uniquely identifies the measurement unit's identification code and transmits it to the main antenna; the main antenna receives the identification code and transmits it to the analysis unit. Furthermore, the analysis unit identifies the measurement unit based on the received and transmitted identification codes.

8. The method according to any one of claims 1 to 3, characterized in that, The converter unit and the secondary antenna are arranged in the secondary housing of the machine tool; the primary antenna is arranged in the primary housing of the machine tool; and the secondary housing and the primary housing are movable relative to each other.

9. The method according to claim 8, characterized in that, For the measuring unit positioned at the measurement location, the sub-housing of the measuring unit is located at a transmission distance from the main housing.

10. The method according to claim 9, characterized in that, The main antenna generates an electromagnetic alternating field; and the transmission distance between the sub-shell and the main shell of the measuring unit located at the measuring position is equal to the range of action of the electromagnetic alternating field.

11. The method according to any one of claims 1 to 3, characterized in that, The sensor is a piezoelectric sensor with a piezoelectric material; the measured variable acts as a tensile and / or compressive load on the piezoelectric material, and the piezoelectric material generates a measurement signal in the form of charge under the action of the measured variable; the converter unit has a charge amplifier that amplifies the charge of the piezoelectric sensor and converts it into a voltage; the converter unit digitizes the voltage into measurement data; the piezoelectric sensor measures the measured variable with a high dynamic measurement resolution up to 35 kHz; and the sub-antenna transmits the measurement data to the main antenna at a transmission rate up to 424 kBit / s.

12. The method according to any one of claims 1 to 3, characterized in that, The sensor is a piezoelectric sensor with a piezoelectric material; the measured variable acts as a tensile and / or compressive load on the piezoelectric material, and the piezoelectric material generates a measurement signal in the form of charge under the action of the measured variable; the converter unit has a charge amplifier that amplifies the charge of the piezoelectric sensor and converts it into a voltage; the converter unit digitizes the voltage into measurement data; the converter unit generates unit data, which represents the unit of the measured variable whose measurement signal has been converted and digitized into measurement data by the converter unit; the converter unit reads the calibration data of the sensor from the data memory of the measurement unit; the converter unit reads the serial number data of the converter unit from the data memory of the measurement unit; and the sub-antenna transmits the unit data, the calibration data, and the serial number data together with the measurement data to the main antenna.

Images