MEASURING UNIT AND MEASURING SYSTEM

Description

[0001] The invention relates to a measuring unit according to claim 1 and a measuring system according to claim 13.

[0002] To collect measurement data in places that are difficult to access or in places that are moving, especially rotating, measuring units are known that transmit measurement signals wirelessly.

[0003] Such measuring units have one or more sensor units for outputting a measurement signal. Sensors of such a measuring unit include, for example, acceleration sensors for detecting acceleration or rotation. The measurement signal is processed by a signal processing unit of the measuring unit, for example, into digital, periodically recorded measurement data. A signal transmission unit of the measuring unit serves to wirelessly transmit the processed measurement signals and has an antenna for this purpose.

[0004] The measuring unit also has two supply connections for connecting an accumulator as an electrical energy storage device to power the measuring unit.

[0005] Such measuring units are known from DE102019112629A1, WO2019122375A1, WO2017068158A1 and DE102004051145B4: The document WO2019122375A1 discloses a measuring unit which is cartridge-shaped in order to be inserted into a corresponding recess of a tool holder.

[0006] Document DE102019112629A1 discloses a clamping device that allows a sensor element to be mounted centrally to the clamping axis. Power is supplied by a rechargeable battery cell.

[0007] WO2017068158A1 discloses a measuring system with a rechargeable energy storage device. The energy storage device can be charged via a charging port or contactlessly via an inductive coupling mechanism. US2006 / 244568 A1 discloses another known measuring system that can be charged contactlessly.

[0008] Such measuring units are often used in boreholes, especially in blind boreholes, to create a mechanically stable and permanent connection with the object to be measured. Especially in applications where movements are measured using the measuring unit, precise adjustment of the measuring unit is typically necessary to position the sensors at the desired measurement locations. It is therefore desirable to not change the position of a measuring unit in the object to be measured.

[0009] The present invention is therefore based on the object of extending the application time of such a measuring unit in a given position and nevertheless enabling a compact design of the measuring unit.

[0010] This object is achieved by a measuring unit according to claim 1 and a measuring system according to claim 13. Advantageous embodiments of the measuring unit can be found in the dependent claims 2 to 12 and advantageous embodiments of the measuring system in the dependent claims 14 and 15.

[0011] The measuring unit according to the invention has at least two supply connections for connecting at least one electrical energy storage device, in particular an accumulator, to supply the measuring unit with electrical energy. Furthermore, the measuring unit has at least one sensor unit for outputting a measurement signal, at least one signal processing unit for processing the measurement signal from the sensor unit, and at least one signal transmission unit with at least one antenna. The antenna has at least one antenna pole.

[0012] The signal processing unit and the signal transmission unit are designed to cooperate in order to transmit the processed measurement signals via the antenna.

[0013] It is essential that the measuring unit has a separating switch which is connected to the antenna pole, the signal processing unit and to one of the supply connections and is designed to form a connection between the signal processing unit and the antenna pole for transmitting the processed measurement signals for high-frequency signals and at least one attenuated, preferably no connection for high-frequency signals between the antenna pole and the supply connection connected to the separating switch and to charge an energy storage device connected to the supply connections for low-frequency signals a connection between the antenna pole and the supply connection for charging the energy storage device connected to the supply connection connected to the separating switch and at least one attenuated,Preferably, no connection for low-frequency signals is formed between the antenna pole and the signal processing unit and that the antenna pole can be electrically contacted on an external side of the signal transmission unit.

[0014] The present invention is based on the finding that, for typical applications, it is advisable to arrange at least one antenna pole of the measuring unit's antenna on an outside side when installed, to achieve high radiation power. Such an antenna pole is thus generally easily accessible without the measuring unit having to be moved or removed from the object to be measured. The measuring unit according to the invention makes it possible to use an antenna pole of the measuring unit's antenna both to transmit the processed measurement signals and to charge an energy storage device connected to the measuring unit's supply connections.

[0015] For this purpose, the measuring unit has the separating switch in order to conduct high-frequency signals from the signal processing unit to the antenna pole, but not to the supply connection, in the case of signal transmission, and to conduct low-frequency signals, in particular direct current, from the antenna pole to the supply connection in the case of charging.

[0016] This enables a compact design, as the antenna pole is also used as an electrical connection for charging the energy storage device.

[0017] In particular, it is advantageous for a housing of the measuring unit to be electrically conductive and to serve as the opposite pole of the electrical connection for charging the energy storage device. This is advantageous because no additional connections for charging the energy storage device need to be provided, and only the antenna pole of the antenna needs to be accessible to enable charging of the energy storage device without removing or moving the measuring unit. The opposite pole for charging the electrical energy storage device can be contacted in a simple manner via the housing of the measuring unit, directly or indirectly via another component that is electrically connected to the housing of the measuring unit, such as a tool holder into which the measuring unit is inserted.

[0018] The separating switch is preferably designed as a passive separating switch, so that no active switching signal is necessary for the separating switch for charging or transmitting, wherein for low-frequency signals only a connection is formed between the antenna pole and the supply connection and for high-frequency signals only a connection is formed between the signal processing unit and the antenna pole.

[0019] This has the advantage that no mechanically moving elements are required. Furthermore, no separate switching signal is required to switch between a transmitting and a charging process, since high-frequency transmit signals are routed from the signal processing unit to the antenna pole, and low-frequency signals during the charging process, especially direct current, are routed from the antenna pole to the supply connection.

[0020] An essential function of the isolating switch is that a connection is established between the signal processing unit and the antenna pole for transmitting the processed measurement signals and for charging an energy storage device connected to the supply connections for low-frequency signals. It is within the scope of the invention that the aforementioned connections may have technical attenuation due to cable paths and / or other electrical and / or electronic components. The advantage is that this results in minimal signal attenuation, if any.

[0021] Preferably, the separating switch is therefore designed such that, for transmitting the processed measurement signals, there is a connection between the signal processing unit and the antenna pole for transmitting the processed measurement signals with an attenuation of less than 20 dB, in particular less than 10 dB, in particular less than 5 dB, and for charging an energy storage device for low-frequency signals connected to the supply connections, there is a connection between the antenna pole and the supply connection for charging the energy storage device connected to the supply connection with an attenuation of less than 20 dB, in particular less than 10 dB, in particular less than 5 dB.

[0022] The passive crossover preferably comprises known electrical and / or electronic elements for frequency-dependent signal separation, in particular coils and capacitors. The crossover is preferably designed as a crossover, particularly preferably as a passive crossover, particularly preferably as a frequency-dependent voltage divider.

[0023] When signals are separated based on frequency, even on lines where no connection is intended for the signal in question, the connection is typically not completely interrupted for technical reasons, but only a high level of attenuation is achieved.

[0024] Preferably, the separating switch is designed such that an attenuation of at least 10 dB, preferably at least 20 dB, in particular at least 30 dB, most particularly at least 40 dB can be achieved for high-frequency signals between the antenna pole and the supply connection compared to a non-attenuated connection.

[0025] The separator is designed such that, for high-frequency signals, a connection exists between the signal processing unit and the antenna pole for transmitting the processed measurement signals. This connection preferably has only a technically determined low, preferably no, attenuation for high-frequency signals. In specific embodiments, slight attenuation due to cable paths or other electrical elements cannot typically be avoided. The separator is advantageously designed such that the connection between the signal processing unit and the antenna pole for transmitting the processed measurement signals has an attenuation of less than 30 dB, preferably less than 20 dB, particularly preferably less than 10 dB, preferably less than 5 dB, particularly preferably less than 2 dB, in particular less than 1 dB.

[0026] Preferably, the separating switch is designed such that an attenuation of at least 30 dB, in particular 50 dB, preferably 75 dB, particularly preferably 100 dB, preferably 120 dB, particularly preferably 150 dB, in particular 200 dB can be achieved for low-frequency signals between the signal processing unit and the antenna pole compared to a non-attenuated connection.

[0027] The separating switch is designed such that, for low-frequency signals, a connection exists between the antenna pole and the supply connection for charging the energy storage device connected to the supply connection. This connection should not exhibit any attenuation for low-frequency signals. In specific embodiments, slight attenuation due to cable paths or other electrical elements cannot typically be avoided. Advantageously, the separating switch is designed such that the connection between the antenna pole and the supply connection for charging the energy storage device connected to the supply connection has an attenuation of less than 30 dB, preferably less than 20 dB, more preferably less than 10 dB, particularly preferably less than 5 dB, in particular less than 1 dB.

[0028] The crossover frequency of a crossover is defined here as the frequency at which the attenuation of the low-frequency signals and the attenuation of the high-frequency signals are equivalent.

[0029] In an alternative preferred embodiment, the separating switch is designed as an actively switchable separating switch, which can be switched between a charging state and a transmitting state by means of a switching signal. In the charging state, a connection is formed for low-frequency signals between the antenna pole and the supply connection for charging the energy storage device connected to the supply connection, and no connection is formed for low-frequency signals between the antenna pole and the signal processing unit. In the transmitting state, a connection is formed for high-frequency signals between the signal processing unit and the antenna pole for transmitting the processed measurement signals, and no connection is formed for high-frequency signals between the antenna pole and the supply connection. This enables a clear specification of the desired state (charging state or transmitting state) by active switching.

[0030] Advantageously, the separating switch is designed to be switchable between the charging state and the transmitting state by means of an electrical switching signal, an electromagnetic wave switching signal, or a magnetic switching signal. An electrical switching signal is preferably transmitted via switching terminals that can be connected to an external circuit. In the advantageous embodiment of a separating switch switchable by means of an electromagnetic wave switching signal, the measuring unit preferably has a receiver for electromagnetic wave switching signals, which is connected to the separating switch in order to transmit received switching signals to the separating switch.In the advantageous embodiment of a separating switch that can be actively switched by means of a magnetic switching signal, the measuring unit preferably has a magnetic-field-sensitive element connected to the actively switchable separating switch in order to transmit a switching signal to the separating switch depending on the presence of a magnetic field. It is particularly advantageous that, when a magnetic field is applied, the separating switch is switched directly under the influence of the magnetic field.

[0031] It is particularly advantageous that the actively switchable separator is designed such that, in the charging state, there is only an electrically conductive connection between the antenna pole and the supply connection, and no electrically conductive connection between the antenna pole and the signal processing unit. In the transmitting state, there is only an electrically conductive connection between the antenna pole and the supply connection, and no electrically conductive connection between the antenna pole and the signal processing unit. It is therefore particularly advantageous that the actively switchable separator is designed as an actively switchable changeover switch.

[0032] Advantageously, the actively switchable switch is designed as a switching relay, in particular for switching between the charging state and the transmitting state by means of an electrical switching signal. In an alternative advantageous embodiment, the actively switchable switch is designed as a reed switch, in particular for switching between the charging state and the transmitting state depending on the presence of a magnetic field.

[0033] The typical frequency ranges for signal transmission of the processed measurement signals are significantly higher than the frequency during the charging process. Advantageously, the high-frequency and low-frequency signals are separated by at least one crossover frequency.

[0034] The high-frequency signals therefore have frequencies greater than the crossover frequency and the low-frequency signals have frequencies less than the crossover frequency.

[0035] In an advantageous embodiment, the high-frequency and low-frequency signals are divided by a first and a second crossover frequency, wherein the first crossover frequency is lower than the second crossover frequency, the low-frequency signals are lower than the first crossover frequency, and the high-frequency signals are higher than the second crossover frequency. Advantageously, the difference between the second crossover frequency and the first crossover frequency is at least 1 MHz, preferably at least 10 MHz, particularly preferably at least 100 MHz.

[0036] The separation frequency or, in the preferred embodiment with a first and a second separation frequency, both separation frequencies are preferably in a frequency range whose upper limit depends on the frequency of the high-frequency signals for transmitting the measurement signal and whose lower limit is preferably 0.1 Hz, in particular 1 Hz, in particular 10 Hz, in particular 55 Hz, in particular 65 Hz, in particular 100 Hz, in particular 1 kHz, in particular 500 kHz, preferably 1 MHz, preferably 5 MHz, more preferably 9 MHz.

[0037] The upper limit of the frequency range of the crossover frequency is preferably less than 70000 MHz, in particular less than 24000 MHz, in particular less than 5000 MHz, in particular less than 1 GHz, in particular less than 800 MHz.

[0038] Preferably, the upper limit of the frequency range of the crossover frequency is selected depending on the frequency range of the high-frequency signals: If the high-frequency signals are in the range from 860 MHz to 930 MHz, the upper limit of the frequency range of the crossover frequency is preferably less than 800 MHz, in particular less than 500 MHz, in particular less than 280 MHz. If the high-frequency signals are in the range from 2400 MHz to 2500 MHz, the upper limit of the frequency range of the crossover frequency is preferably less than 2400 MHz, in particular less than 1 GHz, in particular less than the upper frequency limits already mentioned for the previous case.If the high-frequency signals are in the range from 5100 MHz to 5880 MHz, the upper limit of the frequency range of the crossover frequency is preferably less than 5000 MHz, in particular less than 3000 MHz, in particular less than 2400 MHz, in particular less than the upper frequency limits already mentioned for the previous case. If the high-frequency signals are in the range from 24000 MHz to 24250 MHz, the upper limit of the frequency range of the crossover frequency is preferably less than 24000 MHz, in particular less than 23000 MHz, in particular less than 10000 MHz, in particular less than 6000 MHz, in particular less than the upper frequency limits already mentioned for the previous case.If the high-frequency signals are in the range from 57000 MHz to 71000 MHz, the upper limit of the frequency range of the crossover frequency is preferably less than 70000 MHz, in particular less than 50000 MHz, in particular less than 25000 MHz, in particular less than the upper frequency limits already mentioned for the previous case.

[0039] The separating switch is thus preferably designed such that for signals with a frequency greater than the crossover frequency - high-frequency signals - a connection with at most a weakly attenuated connection is formed between the signal processing unit and the antenna pole for transmitting the processed measurement signals and no connection, or a strongly attenuated connection, is formed between the antenna pole and the supply connection and for signals with a frequency less than the crossover frequency a connection is formed between the antenna pole and the supply connection for charging the energy storage device connected to the supply connection and no connection is formed between the antenna pole and the signal processing unit.

[0040] The separating switch is preferably designed such that the connection between the signal processing unit and the antenna pole for the low-frequency signals has an attenuation of at least 30 dB, in particular 50 dB, preferably 75 dB, particularly preferably 100 dB, preferably 120 dB, compared to a non-attenuated connection in order to block signal transmission on this signal path as far as possible.

[0041] Advantageously, the separating switch is designed such that the connection between the antenna pole and the supply connection for low-frequency signals has an attenuation of less than 30 dB, preferably less than 20 dB, particularly preferably less than 10 dB, preferably less than 5 dB, particularly preferably less than 2 dB, in particular less than 1 dB compared to a non-attenuated connection in order to enable good signal transmission on this signal path.

[0042] In addition, the separating switch is preferably designed such that the connection between the signal processing unit and the antenna pole for the high-frequency signals for transmitting the processed measurement signals has an attenuation of less than 30 dB, preferably less than 20 dB, particularly preferably less than 10 dB, preferably less than 5 dB, particularly preferably less than 2 dB, in particular less than 1 dB compared to a non-attenuated connection in order to enable good signal transmission on this signal path.

[0043] Preferably, the separating switch is designed such that the connection between the antenna pole and the supply connection for charging the energy storage device connected to the supply connection for the high-frequency signals for transmitting the processed measurement signals has an attenuation of at least 10 dB, preferably at least 20 dB, in particular at least 30 dB, very particularly at least 40 dB compared to a non-attenuated connection in order to block signal transmission on this signal path as far as possible.

[0044] The high-frequency signals preferably have a frequency which is preferably less than 100 GHz, preferably less than 50 GHz, preferably less than 10 GHz, more preferably less than 5.9 GHz, in particular less than 2.5 GHz.

[0045] Preferably, the frequency of the high-frequency signals is in the range 2300 MHz to 71000 MHz, in particular in one or more, preferably in one of the following frequency ranges: 860MHz to 930MHz; 863MHz to 870MHz; 902MHz to 928MHz; 2400MHz to 2500MHz; 2401MHz to 2481MHz; 5100MHz to 5880MHz; 5720MHz to 5880MHz; 24000MHz to 24250MHz; 57000MHz to 71000MHz.

[0046] The measuring unit preferably has an electrically conductive housing. An electrically conductive housing has the advantage that the housing can be used as a ground line and / or ground terminal, preferably by contacting the ground terminal of the electrical energy storage device. Furthermore, an electrical connection with an electrically conductive object, in particular a metallic object, into which the measuring unit is inserted, can be formed in a cost-effective manner via an electrically conductive housing.

[0047] Advantageously, the measuring unit has a ferromagnetic housing. This allows a charging port, as described below, to be easily and detachably attached to the measuring unit.

[0048] The antenna of the measuring unit is preferably designed as a monopole antenna or dipole antenna.

[0049] It is particularly advantageous to design the antenna as a monopole antenna. This allows an electrically conductive housing of the measuring unit and / or an electrically conductive object on which the measuring unit is arranged or in which the measuring unit is arranged to be used as the ground pole of the antenna. It is therefore particularly advantageous for the antenna to be designed as a monopole antenna and the ground pole to be connected to an electrically conductive housing of the measuring unit and / or for the measuring unit to have a ground pole contact to contact an external metallic object, in particular a metallic object in which the measuring unit is arranged, as the ground pole.

[0050] When designing the antenna as a monopole antenna, it is advantageous for the signal transmission unit to have an outer plane with the antenna pole and an inner plane with a ground pole, forming the monopole antenna. This achieves advantageous radiation characteristics.

[0051] It is within the scope of the invention that the separating switch is directly connected to the supply connection for charging the energy storage device via an electrical line. It is also within the scope of the invention that additional electrical or electronic components, in particular resistors or control units such as charge controllers, are arranged in the line path between the separating switch and the supply connection.

[0052] The electrically contactable antenna pole preferably has a metallic surface for electrical contact. It is advantageous if the surface of the electrically contactable antenna pole is coated, preferably gold-plated. This promotes a permanently high-quality electrical contact during the charging process.

[0053] The object mentioned above is further achieved by a measuring system according to claim 13. The measuring system comprises a measuring unit according to the invention, in particular a preferred embodiment thereof, and a charging unit with at least one charging connection. The charging connection is designed to be arranged on the antenna pole of the signal transmission unit and has at least one first electrical charging contact, which is arranged such that, when the charging connection is arranged on the antenna pole of the signal transmission unit, there is an electrically conductive contact between the antenna pole and the first charging contact of the charging connection. As a result, the charging process of an electrical energy storage device connected to the measuring unit can be started in a cost-effective manner by arranging the charging connection on the measuring unit.

[0054] The electrical energy storage device connected to the measuring unit is preferably charged using direct current. The signal present at the antenna pole during the charging process is therefore low-frequency, particularly low-frequency at the boundary to 0 Hz.

[0055] Advantageously, the charging connector has a magnet, preferably a permanent magnet, to detachably attach the charging connector to the measuring unit. This ensures easy handling.

[0056] In particular, it is advantageous that, according to the advantageous embodiment described above, the separating switch is designed as a reed switch. In particular, it is advantageous that the magnet of the charging port and the reed switch are designed to interact in such a way that, when the charging port is arranged on the measuring unit, the magnetic field of the magnet of the charging port causes the reed switch of the measuring unit to switch.

[0057] In an advantageous embodiment of the measuring system, the charging port has a second electrical charging contact, which is arranged such that, when the charging port is arranged at the antenna pole of the signal transmission unit, an electrically conductive contact exists between the housing of the measuring unit and the second charging contact of the charging port. The housing of the measuring unit is preferably designed to be electrically conductive or has an electrically conductive mating contact at least in the area where the second electrical charging contact rests against the housing.

[0058] The first electrical charging contact is connected directly or indirectly to the first supply connection via the antenna pole and the second electrical charging contact is connected directly or indirectly to the second supply connection of the measuring unit via the housing of the measuring unit, so that an electrical energy storage device connected to the supply connections of the measuring unit can be charged in a simple manner via the first and second electrical charging contacts.

[0059] The charging unit preferably has a transformer for galvanic potential isolation between the potential of the measuring unit during the charging process and the potential of the supply voltage of the charging unit.

[0060] The charging unit is preferably designed such that during the charging process it generates a direct current for charging the energy storage device connected to the supply terminals.

[0061] The energy storage device is preferably designed to be rechargeable. It is within the scope of the invention to design the energy storage device as an accumulator or as a capacitive energy storage device, in particular as a capacitor, preferably as a supercapacitor.

[0062] The signal transmission unit is preferably designed and arranged such that the antenna pole can be electrically contacted on an outer side of the signal transmission unit.

[0063] Further advantageous features and embodiments are explained below with reference to the figures and exemplary embodiments. Herein: Figure 1 shows a first embodiment of a measuring unit according to the invention with a monopole antenna in the transmitting state; Figure 2 shows the embodiment according to Figure 1 in the charging state; Figure 3 shows a second embodiment of a measuring unit according to the invention with a monopole antenna in the transmitting state; Figure 4 shows the embodiment according to Figure 3in the charging state; Figure 5 shows a third embodiment of a measuring unit according to the invention with a dipole antenna in the transmitting state; Figure 6 shows the third embodiment according to Figure 5 in the charging state; Figure 7 shows a detailed view of the monopole antenna of the first and second embodiments; Figure 8 shows the measuring unit of the first embodiment installed in a tool holder; Figure 9 shows the measuring unit of the first embodiment installed in a measuring sleeve for turning tools and other bars; Figure 10 shows an embodiment of a separating switch for the first and third embodiments of the measuring unit; Figure 11 shows an embodiment of a separating switch for the modification of the second embodiment of the measuring unit.

[0064] All figures are schematic representations, not to scale. Identical reference symbols in the figures indicate identical or identically functioning elements.

[0065] The Figures 1 to 6The illustrated embodiments are designated a, b, c, and m for the circuit description. These designations are explained in Figure 10 and Figure 11.

[0066] The Figures 1 to 6 The illustrated embodiments of measuring units have circular-cylindrical housings 3. In each figure, a section through the cylinder axis is shown.

[0067] The embodiments shown in the figures are designed to be arranged in a blind hole, in this case in a blind hole of a tool holder.

[0068] The Figures 1 and 2 The first exemplary embodiment of a measuring unit according to the invention shown has two supply connections for connecting an electrical energy storage device 1 designed as an accumulator for supplying the measuring unit with electrical energy.

[0069] A first supply connection 2a is connected to the positive pole of the electrical energy storage device 1. A second supply connection 2b is connected to the electrically conductive housing 3 of the measuring unit. As can be seen in the figures, the electrical energy storage device is first arranged in the blind hole of the tool holder 5, so that one pole of the electrical energy storage device 1 is in contact with the tool holder 5. Since both the tool holder 5 and the housing 3 are electrically conductive, an electrically conductive connection exists between the contact of the electrical energy storage device 1 facing the tool holder 5 and the second supply connection 2b.

[0070] The measuring unit 1 has a sensor unit 4, which in this case has an acceleration sensor for detecting a rotational movement of the tool holder. The sensor unit 4 is connected to a signal processing unit 6 in order to output a measurement signal from the sensor of the sensor unit 4 to the signal processing unit 6.

[0071] The measuring unit further comprises a signal transmission unit 7 with an antenna having an antenna pole 8. The flat antenna pole 8 is arranged at the outer end of the measuring unit opposite the first supply connection 2a.

[0072] Signal processing unit 6 and signal transmission unit 7 are designed to cooperate in order to transmit the processed measurement signals by means of the antenna, in particular the antenna pole 8.

[0073] The antenna is in Figures 1 to 4designed as a monopolar antenna (monopole antenna) with the antenna pole 8. The ground pole of the monopolar antenna is formed by the housing 3 of the measuring unit, parts of the tool holder 5, and a ground pole plane 9. The antenna pole 8 and the ground pole plane 9 are designed as circular disks and arranged concentrically in the signal transmission unit 7. The ground pole plane 9 has an opening in its center to enable electrical contact with the antenna pole 8 without contacting the ground pole plane.

[0074] The measuring unit 1 has a separator 10, which in the first embodiment is designed as a frequency divider. The separator 10 is connected to the antenna pole 8, the signal processing unit 6, and the supply connection 2a.

[0075] The crossover network 10 is designed as a crossover network with a crossover frequency of 1 GHz, so that for high-frequency signals greater than the crossover frequency, a connection is formed between the signal processing unit 6 and the antenna pole 8 for transmitting the processed measurement signals, while no connection for such high-frequency signals is formed between the antenna pole 8 and the supply connection 2a. For low-frequency signals with a lower crossover frequency, the design of the crossover network as a crossover network ensures a connection between the antenna pole 8 and the supply connection 2a, and no connection for such low-frequency signals is formed between the antenna pole 8 and the signal processing unit 6.

[0076] It is therefore possible without actively switching to Figures 1 and 2 The measuring unit shown can be operated in a transmitting state or a charging state.

[0077] In the Figure 1In the transmission state shown, the measurement signal, processed as a wave signal, is transmitted from the signal processing unit 6 via the separating switch 10 to the antenna pole 8. The measuring unit also has a voltage regulator 11. This serves to supply the signal processing unit and the sensor unit with the required stabilized supply voltage and to achieve isolation from the reference ground.

[0078] The signal processing unit 6 is connected to the voltage regulator 11 and is supplied with electrical energy by it. Furthermore, the voltage regulator 11 provides a ground connection between the signal processing unit 6 and the second supply terminal 2b and the ground pole plane 9, in order to form the ground pole of the monopolar antenna via the ground pole plane 9, the housing 3, and parts of the tool holder 5. Schematically, Figure 1The field lines of electromagnetic waves during the transmission process are shown as dashed lines.

[0079] In Figure 2 The charge status of the measuring unit is shown. For this purpose, a charging port 12 is arranged on the housing 3 and the signal transmission unit 7 of the measuring unit. The charging port has a first electrical charging contact 13a and a second electrical charging contact 13b, which are arranged such that, when the charging port 12 is arranged on the measuring unit, the first charging contact 13a is electrically connected to the antenna pole 8 and the second charging contact 13b is electrically connected to the housing 3.

[0080] In Figure 2Thus, an embodiment of a measuring system according to the invention is schematically shown, with a charging unit which, in addition to the charging connection 12 already described, has a transformer 14 with which the external supply voltage of the charger is galvanically separated from the DC voltage of 4.2 V in the charger, so that the zero potential of the internal DC voltage is independent of the zero potential of the external supply voltage of the transformer 14.

[0081] As in Figure 2As shown, there is a connection for the DC voltage via the isolating switch 10 between the antenna pole 8 and thus the first charging contact 13a and the positive connection of the electrical energy storage device 1. Via the housing 3 and partial areas of the tool holder 5 there is an electrically conductive connection between the second charging contact 13b and the negative pole of the electrical energy storage device 1. It is thus possible to charge the electrical energy storage device 1 without the measuring unit having to be removed from the tool holder and without separate charging connections on the measuring unit being necessary for charging.

[0082] Due to the design of the separating switch 10 as a frequency divider, the transmission state and the charging state can be present simultaneously. It is thus possible for high-frequency signals to be transmitted from the signal processing unit 6 via the antenna pole 8 and for low-frequency signals—in this case, the DC voltage used for charging, which is present at the antenna pole 8 and the housing 3 of the measuring unit—to be used to charge the electrical energy storage device 1.

[0083] The separating switch 10 is as shown in Figure 10 and the corresponding character description.

[0084] In an advantageous development of the first embodiment, the signal processing unit 6 is additionally designed as a receiving unit to receive start and stop signals for starting and ending the transmission of measurement signals. If no transmission of measurement signals is desired during the charging process, in this advantageous development, the transmission of measurement signals can be stopped by sending the stop signal to the signal processing unit 6. After the charging process, the transmission of measurement signals can be restarted by sending the start signal to the signal processing unit 6.

[0085] In the Figures 3 and 4 a second embodiment of a measuring unit according to the invention is shown, which in the majority of the technical features with the one shown in the Figures 1 and 2illustrated first embodiment. To avoid repetition, the essential differences are explained below: The separating switch 10 of the second embodiment is designed as an electrical toggle switch, in this case as a reed contact. The reed contact is arranged such that, without the application of a magnetic field, there is an electrically conductive connection between the signal processing unit 6 and the antenna pole 8 and no electrically conductive connection between the antenna pole 8 and the first supply connection 2a. When a magnetic field is applied, the reed contact switches, so that there is no electrically conductive connection between the antenna pole 8 and the signal processing unit 6, but there is an electrically conductive connection between the antenna pole 8 and the first supply connection 2a.

[0086] In an alternative embodiment of the second embodiment, the crossover is designed as a passive crossover, just as in the first embodiment. In this alternative embodiment of the second embodiment, the crossover 10 is designed as shown in Figure 10 and the corresponding character description.

[0087] The Figure 4 The charging port 12 shown additionally has two permanent magnets 15a and 15b. These are arranged such that, on the one hand, the charging port 12 can be detachably attached to the measuring unit. Furthermore, the magnetic field of the permanent magnets 15a and 15b causes the reed contact to switch, thus switching from the transmit state to the charging state of the measuring unit.

[0088] As in the Figures 3 and 4 As can be seen, the electrical energy storage device 1 has reversed polarity compared to the one shown in the Figures 1 and 2illustrated first embodiment, so that in the second embodiment, the positive pole of the electrical energy storage device 1 is in contact with the tool holder 5 and thus with the housing 3 and the second supply connection 2b, and correspondingly the negative pole of the electrical energy storage device is in contact with the first supply connection 2a. Accordingly, in contrast to the first embodiment, the ground pole plane 9 of the antenna of the measuring unit is not connected to the housing 3 of the measuring unit, but to the first supply connection 2a.

[0089] In the Figure 3In the transmission state shown, due to the arrangement of the electrical energy storage device, it is necessary that, on the one hand, for high-frequency signals, there is a connection between the negative pole of the electrical energy storage device 1 and the second supply connection 2b, and thus the housing 3 and the tool holder 5, in order to form the ground pole of the monopolar antenna together with the ground pole plane 9. Likewise, in the transmission state, it is necessary that for the direct current supply by the electrical energy storage device 1 and thus for low-frequency signals, there is no connection between the first supply connection 2a and the second supply connection 2b, since otherwise a short circuit would form via the housing 3 and the tool holder 5.

[0090] The measuring unit according to the second embodiment therefore has a second separating switch 16 in addition to the separating switch 10. This is designed as a capacitor, which is arranged between the positive and negative terminals of the voltage regulator 11.

[0091] A detailed view of the monopole antenna of the first and second embodiments according to the Figures 1 to 4 is in Figure 7The illustration shows the advantageous arrangement that the signal transmission unit 6 has an outer plane with the antenna pole 8 and an inner plane with a ground pole in a ground pole plane 9 of the monopole antenna. The arrangement shown in Figure 7 achieves better radiation characteristics. The antenna pole and the ground pole plane are disk-shaped and are positioned concentrically one above the other at a distance d, in this case 2.5 mm. The ground pole plane has a recess; this recess serves to pass through a contact pin 17 of the antenna pole in order to contact the antenna pole 8 on the inner side of the monopole antenna. The contact pin is conductively connected both to the antenna pole and to the separator 10. The antenna pole 8 has a circular contact surface 8a, which is electrically conductive.This contact surface serves as a contact point for contacting the charging contact 13a with the antenna pole 8.

[0092] In the Figures 5 and 6 A further, third embodiment of a measuring unit according to the invention is shown, which in the majority of the technical features with the one shown in the Figures 1 to 4 To avoid repetition, the main differences are explained below: In contrast to the previously discussed versions with monopole antennas, Figure 5The third embodiment is shown with a dipole antenna. The dipole antenna of the third embodiment differs from the monopole antennas of the first and second embodiments in that no ground connection via the housing (ground plane) is required. Due to the symmetrical feeding of the dipole antenna and the direct ground connection by contacting the ground pole of the energy storage device, the housing 3, as well as a tool holder or a measuring collar into which the measuring unit is inserted, can also be made of an electrically non-conductive material.

[0093] The antenna pole 8 and the ground pole 9 are located in one plane on the outside of the signal transmission unit, but are non-conductively connected to each other and together form the dipole antenna. In the transmitting state, the electromagnetic field extends from the antenna pole 8 to the ground pole 9 of the dipole antenna, as shown in the Figures 5shown by the dashed lines. In the illustrated transmission state, the measurement signal, processed as a wave signal, is transmitted from the signal processing unit 6 via the separator 10 to the antenna pole of the dipole antenna. The ground pole 9 of the antenna is directly connected to the ground pole of the energy storage device. In this exemplary embodiment, the housing 3 additionally encloses the electrical energy storage device 1, thus enclosing the measuring unit in the area of ​​the energy storage device.

[0094] In Figure 6 is that previously in Figure 5 The third embodiment shown is shown in the charging state. The difference to the charging states shown in the first and second embodiments according to Figure 2 and Figure 4 lies primarily in the arrangement of the charging contacts. The charging contacts 13a and 13b of the Figure 6directly contact the antenna pole 8 and the ground pole 9 of the measuring unit's dipole antenna. The functionality of the separator of the third embodiment corresponds to the functionality of the separators of the first and second embodiments.

[0095] In an alternative embodiment of the first and third embodiments, the separating switch is designed as an active separating switch (reed contact) as described in the second embodiment. In this case, the charging connection accordingly has a permanent magnet to cause the reed contact to switch during charging.

[0096] An exemplary representation of an installed measuring unit in the transmitting state in a tool holder 5 is shown in Figure 8The measuring unit with monopole antenna is housed in the blind hole on the side of the tool holder. The measuring unit is inserted into the blind hole so far that the sensor unit is in the rotational axis of the tool holder. Figure 8 The field lines of the electromagnetic waves during the transmission process between the antenna pole and the housing are shown schematically as lines. The tool holder 5 is shown schematically in the Figures 1 to 6 with the areas surrounding the measuring unit on three sides.

[0097] Another example arrangement is a measuring cuff, which is Figure 9The measuring unit is mounted within a measuring sleeve 18. The sleeve shape allows the measuring unit to be positioned relative to an element, preferably on cylindrical elements such as rods and struts, in particular on turning tools. For this purpose, the sleeve has an opening for the passage of an element and a blind hole running perpendicular to it, which lies outside the passage. The measuring unit is positioned in this blind hole so that the outer side of the signal transmission unit is freely accessible.

[0098] In Figure 10An embodiment of a separating switch of a measuring unit according to the invention for the measuring unit according to embodiment 1 and embodiment 3 is shown. The separating switch 10 is designed in this case as a passive separating switch using a frequency-dependent voltage divider. The separating switch 10 has three terminals a, b and c. A capacitor C is connected between the terminals a and c. A coil L is connected between the terminals b and c. The designation m denotes Figure 10 The designations a, b, c and m are also used in the examples in Figures 1 and 2 as well as 5 and 6.

[0099] In this exemplary embodiment, the capacitor C has a capacitance of 15 pF and the coil has an inductance of 33 nH. Terminal a of the separator is connected to the output of the signal processing unit. Terminal b of the separator is connected to one of the supply terminals of the electrical energy storage device 1. Terminal c of the separator is connected to the antenna pole 8 of the signal transmission unit 7. The capacitor C forms a high reactance for low-frequency signals, so that the low-frequency signals between the antenna pole (terminal c) and the signal processing unit (terminal a) are subject to strong attenuation and thus there is essentially no connection (a connection with very high attenuation) for low-frequency signals between the antenna pole and the signal processing unit.

[0100] The coil L of the separator creates a reactance for low-frequency signals, so that the low-frequency signals between the antenna pole (connection a) and the power supply connection (connection b) of the electrical energy storage device are subject to low attenuation. For low-frequency signals, a connection (with low attenuation) thus exists between the antenna pole and the power supply connection.

[0101] In the case of the exemplary embodiment, capacitor C forms a low reactance for high-frequency signals, so that the high-frequency signals between the signal processing unit (connection a) and the antenna pole (connection c) are subject to low attenuation. For high-frequency signals, a connection (with low attenuation) thus exists between the signal processing unit and the antenna pole.

[0102] The coil L of the separator presents a high reactance for high-frequency signals, so that the high-frequency signals between the antenna pole (connection c) and the supply connection (connection b) of the electrical energy storage device are subject to significant attenuation. For high-frequency signals, there is essentially no connection (a connection with very high attenuation) between the antenna pole (connection c) and the supply connection (connection b) of the electrical energy storage device.

[0103] The present configuration of the Figure 10 The crossover shown is particularly suitable for low-frequency signals in the range 0 Hz to 10 Hz and for high-frequency signals in the range 2400 MHz to 2480 MHz.

[0104] In Figure 11A further embodiment of a first separating filter 10 of a measuring unit according to the invention is shown, modified from the second embodiment (implemented as a passive frequency separator). In this case, the separating filter 10 is designed as a passive separating filter in the form of a frequency-dependent voltage divider. The separating filter 10 has three terminals a, b and c. A capacitor C is connected between the terminals a and c. A coil L is connected between the terminals b and c. The designation m also denotes Figure 11 In addition to the first isolating switch, Figure 11 the second separating switch 16 is shown. In the illustrated embodiment, the second separating switch has a capacitor C 2. This capacitor C 2 is connected between the terminal b and the reference potential m. The designations a, b, c and m are also used in the embodiments in Figures 3 and 4 attached.

[0105] In this exemplary embodiment, the capacitor C has a capacitance of 15 pF and the coil has an inductance of 33 nH. Terminal a of the first separating switch is connected to the output of the signal processing unit. Terminal b of the first separating switch is connected to one of the supply terminals of the electrical energy storage device 1. Terminal c of the first separating switch is connected to the antenna pole 8 of the signal transmission unit 7. The capacitor C forms a high reactance for low-frequency signals, so that the low-frequency signals between the antenna pole (terminal c) and the signal processing unit (terminal a) are subject to strong attenuation and thus there is essentially no connection (a connection with very high attenuation) for low-frequency signals between the antenna pole and the signal processing unit.

[0106] The capacitor C 2 of the second separating switch forms a high reactance for low-frequency signals, so that the low-frequency signals between the supply connection of the electrical energy storage device 1 and the opposite pole of the electrical energy storage device 1 are subject to strong attenuation and thus there is essentially no connection (a connection with very high attenuation) for low-frequency signals between the antenna pole and the signal processing unit.

[0107] Coil L of the first separator creates a reactance for low-frequency signals, so that the low-frequency signals between the antenna pole (connection a) and the power supply connection (connection b) of the electrical energy storage device are subject to low attenuation. For low-frequency signals, a connection (with low attenuation) thus exists between the antenna pole and the power supply connection.

[0108] In the case of the exemplary embodiment, the capacitor C of the first separator provides a low reactance for high-frequency signals, so that the high-frequency signals between the signal processing unit (connection a) and the antenna pole (connection c) are subject to low attenuation. For high-frequency signals, a connection (with low attenuation) thus exists between the signal processing unit and the antenna pole.

[0109] The capacitor C 2 of the second separating switch forms a low reactance for high-frequency signals, so that the high-frequency signals are separated between the ground pole / ground pole plane and reference potential m (see Figure 3 ) are subject to a low attenuation. For high-frequency signals, there is a connection (with low attenuation) between ground pole / ground pole plane and thus form the reference potential m (dashed in Figure 3 ) out of.

[0110] Coil L of the first separator presents a high reactance for high-frequency signals, so that the high-frequency signals between the antenna pole (connection c) and the supply connection (connection b) of the electrical energy storage device are subject to significant attenuation. Thus, there is essentially no connection (a connection with very high attenuation) between the antenna pole (connection c) and the supply connection (connection b) of the electrical energy storage device.

[0111] The present configuration of the Figure 11 The crossover shown is particularly suitable for low-frequency signals in the range 0 Hz to 10 Hz and for high-frequency signals in the range 2400 MHz to 2480 MHz. Reference symbol

[0112] 1 Electrical energy storage device 2a First supply connection 2b Second supply connection 3 Housing 4 Sensor unit 5 Tool holder 6 Signal processing unit 7 Signal transmission unit 8 Antenna pole 8a Contact surface 9 Ground pole plane 10 Isolating switch 11 Voltage regulator 12 Charging connection 13a First charging contact 13b Second charging contact 14 Transformer 15a, 15b Permanent magnets 16 Second isolating switch 17 Contacting pin 18 Sleeve

Claims

1. Measuring unit, with at least two supply connections (2a, 2b) for connecting at least one electrical energy storage device (1) for supplying the measuring unit with electrical energy, at least one sensor unit (4), for outputting a measuring signal, at least one signal processing unit (6) for processing the measuring signal from the sensor unit (4), at least one signal transmission unit (7) with at least one antenna with at least one antenna pole (8), wherein the signal processing unit (6) and the signal transmission unit (7) are designed to cooperate, in order transmit the processed measuring signals by means of the antenna, characterized in that, the measuring unit has a combiner (10), which is connected to the antenna pole (8), to the signal processing unit (6) and to one of the supply connections (2a, 2b) and is designed, to transmit the processed measuring signals for high-frequency signals, to form a connection between the signal processing unit (6) and the antenna pole (8) for transmitting the processed measuring signals, as well as to form at least one damped, preferably no connection, for high-frequency signals between the antenna pole (8) and the supply connection and, in order to charge an energy storage device (1) connected to the supply connections (2a, 2b) for low-frequency signals, to form a connection between the antenna pole (8) and the supply connection for charging the energy storage device (1) connected to the supply connection, as well as to form at least one damped, preferably no connection, for low-frequency signals between the antenna pole (8) and the signal processing unit (6) and in that the antenna pole (8) can be electrically contacted on an external side of the signal transmission unit (7).

2. Measuring unit according to claim 1, characterized in that the combiner (10) is designed as a passive combiner (10), such that only one connection is formed between the antenna pole (8) and the supply connection for low-frequency signals and only one connection is formed between the signal processing unit (6) and the antenna pole (8) for high-frequency signals.

3. Measuring unit according to claim 2, characterized in that the combiner (10) is designed as a frequency diplexer, preferably as a passive frequency diplexer, in particular as a frequency-dependent voltage divider.

4. Measuring unit according to claim 1, characterized in that the combiner (10) is designed as an actively switchable combiner (10), which is designed to be switchable by means of a switching signal between a charging state and a transmitting state, wherein, in the charging state for low-frequency signals, a connection is formed between the antenna pole (8) and the supply connection for charging the energy storage device (1) connected to the supply connection, and no connection is formed for low-frequency signals between the antenna pole (8) and the signal processing unit (6) and, in the transmitting state for high-frequency signals, a connection is formed between the signal processing unit (6) and the antenna pole (8), and no connection is formed for high-frequency signals between the antenna pole (8) and the supply connection, wherein preferably, in the charging state, an electrically conductive connection is formed between the antenna pole (8) and the supply connection for charging the energy storage device (1) connected to the supply connection, and no electrically conductive connection is formed between the antenna pole (8) and the signal processing unit (6) and in the transmitting state, an electrically conductive connection is formed between the signal processing unit (6) and the antenna pole (8), and no electrically conductive connection is formed between the antenna pole (8) and the supply connection, in particular, in that the combiner (10) is designed to be switchable between the charging state and the transmitting state by means of an electrical switching signal, an electromagnetic wave switching signal or a magnetic switching signal.

5. Measuring unit according to claim 4, characterized in that the combiner (10) is designed as an actively switchable changeover switch, in particular as a changeover relay or as a reed switch.

6. Measuring unit according to any one of the preceding claims, characterized in that the high-frequency and low-frequency signals are divided by a separation frequency, which is preferably in the range of 1 Hz to 2 GHz, in particular 50 MHz to 2 GHz, preferably 1 GHz to 2 GHz.

7. Measuring unit according to any one of the preceding claims, characterized in that the measuring unit has an electrically conductive housing, preferably a ferromagnetic housing, with at least one opening, on which the antenna is arranged.

8. Measuring unit according to any one of the preceding claims, characterized in that the signal transmission unit (7) has an outer plane with the antenna pole (8) and an inner plane with a ground pole, to form a monopole antenna.

9. Measuring unit according to any one of the preceding claims, characterized in that the combiner (10) is designed such that the connection between the signal processing unit (6) and the antenna pole (8) for low-frequency signals has an attenuation of at least 30 dB, in particular 50 dB, preferably 75 dB, particularly preferably 100 dB, preferably 120 dB, compared to an undamped connection.

10. Measuring unit according to any one of the preceding claims, characterized in that the combiner (10) is designed such that the connection between the antenna pole (8) and the supply connection for low-frequency signals has an attenuation of less than 30 dB, preferably less than 20 dB, particularly preferably less than 10 dB, preferably less than 5 dB, particularly preferably less than 2 dB, in particular less than 1 dB, compared to an undamped connection.

11. Measuring unit according to any one of the preceding claims, characterized in that the combiner (10) is designed such that the connection between the signal processing unit (6) and the antenna pole (8) for high-frequency signals for transmitting the processed measuring signals has an attenuation of less than 30 dB, preferably less than 20 dB, particularly preferably less than 10 dB, preferably less than 5 dB, particularly preferably less than 2 dB, in particular less than 1 dB, compared to an undamped connection.

12. Measuring unit according to any one of the preceding claims, characterized in that the combiner (10) is designed such that the connection between the antenna pole (8) and the supply connection for charging the energy storage device (1) connected to the supply connection for high-frequency signals for transmitting the processed measuring signals has an attenuation of at least 10 dB, preferably at least 20 dB, in particular at least 30 dB, very particularly at least 40 dB, compared to an undamped connection.

13. Measuring system, with a measuring unit according to any one of the preceding claims and a charging unit with at least one charging connection (12), wherein the charging connection (12) is designed to be arranged on the antenna pole (8) of the signal transmission unit (7) and has at least one first electrical charging contact (13a), which is arranged such that, when the charging connection (12) is arranged on the antenna pole (8) of the signal transmission unit (7), there is an electrically conductive contact between the antenna pole (8) and the first charging contact (13a) of the charging connection (12).

14. Measuring system according to claim 13, characterized in that the measuring system is designed to charge the electrical energy storage device (1) connected to the measuring unit by means of a direct current.

15. Measuring system according to any one of claims 13 and 14 and claim 7, characterized in that the charging connection (12) has a second electrical charging contact (13b), which is arranged such that, when the charging connection (12) is arranged on the antenna pole (8) of the signal transmission unit (7), there is an electrically conductive contact between the housing (3) of the measuring unit and the second charging contact (13b) of the charging connection (12).