EP4010662A1

EP4010662A1 - Anchoring device

Info

Publication number: EP4010662A1
Application number: EP20746937.0A
Authority: EP
Inventors: Thomas Buck; Stefano Delfini; Wolfgang PLEUGER; Gerd Scheying; Tjalf Pirk; Joachim Loeblein
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2019-08-07
Filing date: 2020-07-24
Publication date: 2022-06-15
Also published as: WO2021023524A1; CN114222868A; DE102019211867A1; US20220282748A1

Abstract

The invention relates to a measuring device for a fastening device, comprising a base body, a sensor unit which is designed to detect at least one fastening variable, an interface which is connected to the sensor unit and designed to provide the at least one fastening variable to the external reading device. It is proposed that the interface is electrically connectable to a wireless communication unit or directly connectable to the external reading device.

Description

description

title

Anchor device

State of the art

In WO 2013/113586 an anchor system with a sensor for detecting an axial end position of an expansion sleeve is described.

Disclosure of the invention

The invention relates to a measuring device for a fastening device, with a base body, with a sensor unit which is designed to detect at least one fastening quantity, with an interface that is connected to the sensor unit and is designed to provide an external readout device with the at least one fastening device provision size. It is proposed that the interface be electrically connectable to a wireless communication unit or directly connectable to the external readout device. In this way, a simple and inexpensive measuring device can be provided which can be retrofitted with expensive electronics and / or communication. In this way, a particularly inexpensive measuring device can advantageously be implemented, via which the state of a fastening device can be monitored.

The fastening device is in particular a fastening that is used in construction, such as an anchor, a dowel or a screw. An anchor is to be understood as meaning, in particular, a component or an arrangement of components for the secure connection or anchoring of components. The anchor is preferably made of a tensile strength material, preferably a metal. The anchor is designed to be fastened in a borehole. The anchor is in particular designed to be non-positive and / or form-fitting with the material in which the borehole is arranged. Alternatively, it is also conceivable that the anchor is designed such that it can be connected in a materially bonded manner to the material in which the drill hole is arranged. The borehole is designed, in particular, as a substantially cylindrical borehole.

The main body of the measuring device can be formed from a plastic, a ceramic material and / or a metal. The base body can, for example, be designed as an at least partially or partially annular disk, as a circuit board, as a nut or as a washer. In particular, the base body is designed such that the base body is arranged in a force path of the fastening device in the fastened state. The base body can be arranged partially or completely in the force path of the fastening device. The force path of the fastening device should be understood to mean in particular the loading in which a force from the fastening device acts in the fastened state. The base body preferably consists of a composite material.

The sensor unit can have one or more sensor elements for detecting the fastening parameters. The sensor elements can be designed as passive sensor elements or active sensor elements.

An active sensor element is to be understood in particular as a sensor which is designed in such a way that an electrical signal can be generated from the outside without electrical energy. The active sensor element can, for example, be designed as a thermal element, as a light sensor, as a photovoltaic cell or as a pressure sensor, in particular as a piezoelectric pressure sensor. The active sensor element can for example be designed as a piezoelectric or an electrodynamic sensor element. Alternatively or additionally, the active sensor element is designed to generate a mechanical or electromagnetic excitation, a response to this excitation being able to be converted into an electrical signal by the active sensor element. In contrast to the passive sensor element, the active sensor element requires external electrical energy to generate the excitation. The active sensor element can, for example, be a piezoelectric Layer, a sounder, a vibration element or an electronic oscillating circuit can be executed.

A passive sensor is to be understood in particular as a sensor whose parameters are changed by the measured variable. The passive sensor is preferably designed in such a way that the parameter can be changed by the measured variable independently of an applied voltage or energy supply. The conversion into an electrical signal is preferably carried out as soon as electrical energy is available. In particular, electronics can convert this parameter into an electrical signal. The passive sensor can, for example, be designed as an inductive, capacitive, resistive and optical sensor element, or as a pressure, force, inertial, light, humidity, temperature or magnetic field sensor, as a thermocouple or as a microphone.

The electronics can include, for example, an ASIC, an IC or integrated circuit or a microprocessor. Furthermore, the sensor unit or the electronics can comprise a memory unit. The fastening size can be stored at least temporarily in the memory unit. Furthermore, identification information can be stored digitally in the memory unit, via which the fastening device can be identified. The identification information can include, for example, type, model, manufacturer information and / or a unique identification.

The fastening variables are, in particular, physical variables by means of which the state of fastening of the fastening device, the state of the fastening device and / or the state of the material in which the fastening device is attached can be characterized. The fastening size can for example be designed as a force with which the fastening device is attached, for example the compressive force on a nut in the case of an anchor. Alternatively or additionally, the fastening size can also be designed as an orientation of the fastening device, for example a tilting of the nut. It is also conceivable that the fastening size is designed as information relating to the moisture and / or corrosion in the area of the fastening device or a temperature. It is also conceivable that the fastening size is in the form of information relating to the state of the surroundings of the fastening device. The interface can be designed as a wireless interface or as a contact interface. A wireless interface is to be understood in particular as an interface via which the fastening size and / or the identification information can be transmitted wirelessly. The interface can be designed in such a way that the data can be transmitted via, for example, Bluetooth, LoRaWAN, WLAN, ZigBee, NFC, Wibree or WiMAX. In the state connected to the wireless communication unit, the interface is designed as a wireless interface. A contact interface is to be understood in particular as an interface via which data can be exchanged via direct contact with the external readout device. The interface, in particular the contact interface, preferably comprises a contact element which is designed to transmit data by means of an electrical conductor or a light oscillation conductor. The wireless communication unit is preferably designed to be connectable to the contact element of the interface. Advantageously, an interface designed as a contact interface can be converted into a wireless interface via the connection of the wireless communication unit to the interface. The wireless communication unit can be designed as an RFID tag or a SAW tag, for example.

The external readout device has a communication interface via which a signal provided by the interface can be received and can, for example, be designed as a Bluetooth, LoRaWAN, WLAN, ZigBee, NFC, Wibree or WiMAX communication interface. The external read-out device can be designed, for example, as an external read-out device that is particularly battery-operated. The external device can, for example, be designed as a handheld power tool, which is provided in particular for generating the borehole or for fastening the fastening device, such as an anchor, for example. The hand-held power tool can, for example, be designed as a drill, an impact drill, a hammer drill, a screwdriver, an impact screwdriver or the like. It is also conceivable that the external readout device is designed as a device specifically provided for reading out the fastening device or the interface. It is also conceivable that the external readout device is designed as a smartphone, a tablet or a mobile computer, such as a laptop, for example. Alternatively, it is also conceivable that the external readout device is designed as an autonomous device, which the measuring device device autonomously controls and reads, for example a robot or a drone. Alternatively, it is conceivable that the external readout device is designed as a stationary unit which is installed in the area of at least one fastening device, preferably in an area with several fastening devices. Several fastening devices can advantageously be checked periodically by means of the interface via the external readout device, which is designed as a stationary unit, in order to ensure that the anchoring is secure.

The information provided via the interface can be monitored and evaluated during and / or after the fastening device is set in order to store it in an infrastructure or to write it to the memory element. For example, when setting a fastening device in the form of an anchor with a measuring device, this process can be monitored, in particular via an external device designed as a hand-held power tool. Alternatively, the monitoring or the reading out and evaluation can also take place at a distance of a few meters by means of a mobile external reading device. For example, it is conceivable that the memory element is designed as an RFID element and is intended to be modified and / or written to by tools or hand-held power tools placed near the fastening device. The storage takes place, for example, via a physical modification of a resistor or a capacitance, which in turn can be read out through the interface. The information provided via the interface can also be called up at a later point in time.

Furthermore, it is proposed that the sensor unit has a transmission element which is designed to convert a physical input variable into a physical output variable, the attachment variable being detected by the sensor element based on the physical output variable. The transmission element can advantageously make it easier or even make it possible to detect the size of the fastening. The physical input variable can, for example, be a force that acts on the measuring device. It is also conceivable that the physical input variable is a temperature, a pressure or a humidity in the area of the measuring device. Depending on the transmission element, different output variables are conceivable, such as for example a force, an optical variable, an electrical variable, a magnetic cal variable, etc. The transmission element can also be designed in one piece with the sensor element, so that the transmission element is also designed to detect the measured variable.

It is also proposed that the transmission element is designed to be elastic in such a way that the fastening size can be detected via a deformation of the transmission element. Advantageously, a physical input variable in the form of a force can be converted by the transmission element in a simple manner, for example into a force that acts in a different direction and / or into a thickness or length of the transmission element. The transmission element has, in particular, a modulus of elasticity of less than 10, preferably less than 2, preferably less than 0.1. An elastic transmission element is to be understood as meaning in particular an elastically deformable transmission element that changes its shape when a force is applied and returns to its original shape when this force is no longer applied. As an alternative or in addition, the transmission element can also be designed to be plastically deformable, the threshold for the deformation being advantageously chosen such that a proper or improper fastening of the fastening device can be detected or displayed.

It is also proposed that the transmission element is designed in such a way that at least one optical property of the transmission element changes as a function of the physical input variable. The optical property can advantageously be detected by the sensor unit. The optical property can be, for example, the transparency, the refractive index, the reflectivity, the color, etc. of the transmission element.

It is further proposed that the transmission element is designed in such a way that at least one magnetic property changes as a function of the physical input variable. Alternatively or additionally, it is proposed that the transmission element is designed in such a way that at least one electrical property of the transmission element changes as a function of the physical input variable. The magnetic properties can be, for example, a coupling variable, a magnetic susceptibility, a magnetic permeability, a resulting change in the magnetic flux or the flux transfer, to a inductive damping quantity or a changed eddy current behavior. The electrical properties can be, for example, a capacitance of a capacitor, in particular a capacitance of a plate capacitor, an electrical permittivity, an electrical susceptibility or an electrical resistance, in particular a contact resistance.

It is further proposed that the interface has at least one mechanical connection element for the force-fitting and / or form-fitting connection with the wireless one. The force-fit and / or form-fit connection is preferably designed to be releasable without tools. The connection between the interface and the wireless communication unit can thereby advantageously be released in order to connect another measuring device to the wireless communication interface.

It is also proposed that the sensor unit and the interface are arranged at a distance from one another, the sensor element being arranged radially on the inside and the interface being arranged radially on the outside. In particular, the sensor unit is arranged in a force path of the fastening device and the communication unit is arranged outside of the force path of the fastening device. This can advantageously reduce the load on the communication unit. Radially inwardly should be understood in this context, in particular, that when fastened with the fastening device transversely to the connection direction, the distance between the sensor unit and the fastening device is less than the distance between the interface or the wireless communication unit. The interface can be arranged on a top side, a bottom side or on the edge of the measuring device. A top side of the measuring device is to be understood in particular as the side facing away from the workpiece to which the fastening device is attached in the fastened state.

It is also proposed that the interface be connected to the sensor element via an electrical connection element. The electrical connection element can for example be designed as a wire, a cable or as a conductor track. It is also conceivable that the connecting element is designed as a contact electrode, a ring electrode, an array or a matrix of contacts or a coil. The measuring device preferably has a shield which is designed to shield the sensor element and / or the connecting element. The shield can comprise, for example, a shield structure or a mass socket for electrodes. It is also conceivable that the shield comprises at least one shield ring. In this context, shielding is to be understood as meaning in particular suitable shielding against electrical and / or magnetic fields. In this way it can advantageously be ensured that the detection of fastening parameters, which are determined, for example, via a capacitance, are not or hardly falsified.

It is also proposed that the measuring device have a reference structure for comparison with environmental parameters. This can advantageously increase the accuracy of the detection of the fastening size. The reference structure is preferably arranged outside the force path.

It is also proposed that the interface has at least two contact elements, each of which is designed to provide at least one fastening size. As a result, several fastening sizes of the external reading device can advantageously be provided. The contact elements can be formed in the same way, but in particular are not electrically connected to one another. The contact element can be designed, for example, as an electrode, as a plug, as a socket, as a contact pad or the like.

The invention also relates to a system having a measuring device as described above and a wireless communication unit, the wireless communication unit being connected to the measuring device in a materially or non-positively and / or positively locking manner. A measuring device that can wirelessly communicate with an external readout device can thereby advantageously be implemented.

In particular, the invention further relates to a measuring device for a fastening device, with a base body, with a sensor unit that is designed to detect at least one fastening variable, with an interface that is connected to the sensor unit and designed to provide an external readout device to provide the at least one attachment size, the sensor unit having an excitation element for mechanical and / or electrical excitation of the attachment device and a sensor element, the sensor element being designed to provide an attachment size depending on the response to the excitation capture. In this way, energy can advantageously be introduced into the fastening device or its surroundings and the reaction to it measured, the state of the fastening being able to be determined via the determined values. The excitation element can be designed piezoelectrically or electrodynamically, for example. The excitation element can have an active sensor element and / or a passive sensor element. The excitation element is designed in particular to generate a mechanical or electromagnetic excitation, wherein a response to this excitation can be converted into an electrical signal by the sensor element. In particular, electronics can convert the response to the excitation into an electrical signal. The excitation element requires electrical energy to generate the excitation. The excitation element can be designed, for example, as a piezoelectric layer, a sounder, a vibration element or an electronic oscillating circuit. The excitation element and the sensor element can be designed in one piece, the sensor element preferably being designed as an active sensor.

The excitation element is connected in particular to electronics. The electronics can both provide the energy supply for the excitation element and control or regulate the excitation element. The control or regulation takes place via an ASIC, a microcontroller or the like.

Alternatively or additionally, it is also conceivable that the measuring device is designed in such a way that the excitation of the excitation element affects the workpiece or the structure receiving the fastening device.

It is further proposed that the excitation element is designed to generate a mechanical vibration. The mechanical oscillation can in particular be designed as a sound wave. The mechanical oscillation can be designed as a longitudinal and / or transverse wave.

It is also proposed that the sensor unit is designed to detect the fastening size based on the transit time, the intensity, the frequency and / or the direction of the mechanical vibration. A precise detection of the fastening size can thereby advantageously be realized. It is also proposed that the excitation element be designed as a piezo element. The excitation element embodied as a piezo element is preferably embodied in one piece with the sensor element.

Furthermore, it is proposed that the excitation element is designed to carry out an electromagnetic excitation, the sensor element detecting a fastening variable based on an electrical impedance. In particular, the excitation element is designed as a capacitor that is reloaded with different frequencies. A detection of the moisture of the workpiece receiving the fastening device is, for example, conceivable via such an excitation.

In particular, the invention further relates to a system comprising a measuring device as described above and a further measuring device that are wirelessly connected to each other, the further measuring device having a sensor element which is designed to determine a fastening size as a function of the response to the excitation of the Detect excitation element of the measuring device. The further measuring device can be designed essentially identically to the measuring device.

The invention preferably relates to a method for monitoring the status of a fastening device, comprising the following steps:

- Sending a signal from an external readout device to a measuring device which is fastened to a workpiece with a fastening device;

- Receiving the signal by the measuring device;

- Activation of an excitation element of the measuring device as a function of the signal from the external readout device;

- Mechanical and / or electrical excitation of the fastening device and / or the workpiece by the excitation element;

- Detection of the response signal to the excitation of the excitation element by a sensor unit of the measuring device. A fastening variable can advantageously be detected via the response signal and the state of the fastening device and / or the workpiece can thus be determined.

Additional steps are also conceivable, such as: - Provision of the response signal via an interface of the measuring device as described above;

- Evaluation of the response signal by the measuring device or the external readout device;

- Reception of the response signal by the external readout device;

- Determination of a state of the fastening device and / or the workpiece as a function of the response signal;

- Display of the status of the fastening device and / or the workpiece on the external readout device, in particular on a screen of the external readout device.

In particular, the invention also relates to a measuring device for a fastening device, with a base body, with a sensor unit which is designed to detect at least one fastening variable, with an interface which is connected to the sensor unit and is designed to provide an external readout device to provide at least one fastening size, the measuring device having an energy supply unit which is designed to supply a sensor element, an excitation element and / or a communication unit with energy. The measuring device can thereby advantageously be supplied with energy.

It is further proposed that the energy supply unit has an energy absorption element which is designed to convert an external electromagnetic signal for supplying energy to the measuring device. In this way, energy can advantageously be introduced into the measuring device in a simple manner. The external electromagnetic signal is provided by an external energy source that is not part of the measuring device and / or fastening device. The external electromagnetic signal can, for example, be a radio wave or light, in particular special light in the visible range or UV or IR light. The energy absorption element is designed in particular to convert the external electromagnetic signal into an electrical signal or into electrical energy. Further advantageous wavelength ranges are in areas that already permit sufficiently high radio powers in regulatory terms, for example in the areas for RFID, for radar or in generally available areas for communication. It is also proposed that the energy supply unit have an energy storage element. In this way, the energy can advantageously be temporarily stored or accumulated until the required amount of energy for a measurement or a process such as communication with an external readout device is reached. The energy storage element can be designed, for example, as a capacitor, in particular a ceramic capacitor or a tantalum capacitor. As an alternative, it is also conceivable that the energy storage element is an electrochemical accumulator, a supercap or an electrolytic capacitor

It is also proposed that the energy storage element have a capacity of at least 5-500 pF, in particular at least 10-200 pF. This can advantageously ensure that the storage capacity of the energy storage element is sufficiently large.

Furthermore, it is proposed that the energy supply unit be designed such that the energy is stored in the energy storage element until a threshold value is reached, the sensor element, the excitation element and / or the communication element being activated when the threshold value is exceeded.

In particular, the invention further relates to a system consisting of a measuring device as described above and an external energy supply device. The external energy supply unit can be integrated into a building infrastructure unit, such as a smoke detector, for example. The measuring device can thereby advantageously be supplied with energy regularly or as required. It is also conceivable that the energy supply unit is designed as a mobile external energy supply unit that can be worn by a user, such as a smartphone or a flashlight. Alternatively, it is also conceivable that the external energy supply unit is designed as an autonomous device that autonomously controls the measuring device and supplies it with energy, for example a robot or a drone. The excitation or the electromagnetic radiation of the external energy supply device is advantageously optimized for the energy supply unit.

The invention preferably further relates to a method for controlling a measuring device for a fastening device, comprising the following steps: - Activation of an external energy supply unit; Activation can be triggered manually by a user or automatically. The automatic activation can, for example, be time-triggered.

- Provision of energy in the form of an electromagnetic signal by an ex ternal energy supply unit; The external energy supply unit can be portable, autonomously mobile or designed as a stationary device. The external energy supply device can also be the external readout device.

- Conversion of the electromagnetic signal into electrical energy by the energy supply unit;

- Storing the energy by the energy supply unit;

- Control of the measuring device based on a state variable of the Energiever supply unit; In particular, the state variable of the energy supply unit is a fill level of the energy storage unit of the energy supply unit. By controlling the measuring device as a function of a state variable of the energy supply unit, a sufficient energy supply to the measuring device can advantageously be ensured during its activation.

- Provision of the energy to a sensor element, an excitation element and / or a wireless communication unit;

- Activation of the sensor element, the excitation element and / or the wireless communication unit. All electronic components of the measuring device can advantageously be supplied with energy by the energy supply unit.

The individual steps of the method preferably run in the order mentioned above.

drawings

Further advantages emerge from the following description of the drawings. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations. Reference symbols of features of different embodiments of the invention which essentially correspond are provided with the same number and with a letter identifying the embodiment.

Show it:

La is a schematic side view of a first embodiment of a measuring device with a fastening device;

FIG. 1b shows a perspective view of the measuring device according to FIG.

FIG. 1c shows a partial section through the measuring device according to FIG.

2 shows an alternative embodiment of a measuring device;

3 shows a further alternative embodiment of the measuring device;

4 shows a fourth embodiment of the measuring device;

5 shows a fifth embodiment of the measuring device;

6 shows a sixth embodiment of the measuring device;

7 shows a seventh embodiment of the measuring device;

8 shows an eighth embodiment of the measuring device; 9a shows a schematic view of a ninth embodiment of the measuring device;

FIG. 9b shows a schematic view of two measuring devices according to FIG. 9a.

Description of the exemplary embodiments

In Fig. La is a side view of a fastening device 10 with a measuring device 100 is shown. The fastening device 10 is designed in particular for mounting heavy-duty components 12 on walls or ceilings. The fastening device 10 is designed, for example, as an anchor. For this purpose, a borehole 16 is first produced in a workpiece 18 by means of a hand power tool 1004 designed as a hammer drill. The workpiece 18 is designed as a concrete wall with play. The fastening device 10 be made of a metallic material, in particular stainless steel.

For assembly, the heavy-duty component 12 is first positioned on the wall. The fastening device 10 is guided into the borehole 16 via an assembly opening 20 of the heavy-duty component 12, so that a fastening region of the fastening device 10 is arranged within the borehole 16. The fastening device 10 has a front end 22 which is arranged in the borehole 16 in the fastened state. Furthermore, the fastening device 10 has a rear end 24 opposite the front end 22. The rear end 24 is arranged in an area outside the borehole 16 in the fastened state.

The fastening device 10 comprises a tension receiving element 26, via which a tensile force can be introduced onto a base body 28 of the fastening device 10. The tension receiving element 26 is designed, for example, as a thread 30 or as an external thread. The tensile force is introduced via a nut 32 which is connected to the tensile receiving element 26. Furthermore, the fastening device 10 comprises an expansion sleeve 34 which, when the fastening device 10 is fastened in the workpiece 18, secures it by a force acting radially outward.

Furthermore, the fastening device 10 has a washer 36, which is also formed, for example, from a metal or steel. The washer 36 is designed to distribute a force based on the fastening device 10 or the nut 32 over a larger area. The measuring device 100 has a base body 102. The base body 102 is annular and, for example, has a larger diameter than the washer 36. However, it is also conceivable that the lateral extension of the base body 102 is smaller than that of the washer 36 or is adapted to this. Alternatively, it would also be conceivable that the washer 36 and the base body 102 of the measuring device 100 are formed in one piece.

The fastening device 10 is shown in the fastened state in FIG. 1 a, in which the fastening device 10 is arranged in the borehole 16. For fastening, the fastening device 10 is first connected to a washer 36 and then to the measuring device 100.

In a further step, a nut 32 is connected to the fastening device 10. The nut 32 has an internal thread, not shown, which corresponds to the tension receiving element 26 of the fastening device 10, which is designed as a thread 30. First, the nut 32 is screwed onto the fastening device 10 until the nut 32 rests on the washer 36 and the washer 36 rests on the heavy-duty component 12 via the measuring device 100. Subsequently, a torque is transmitted to the nut 32 by means of a tool such as a wrench or a handheld power tool 1004 such as a screwdriver, the torque acting on the nut 32 being transmitted via the train receiving element 26 into a tensile force acting on the fastening device 10 .

The measuring device 100 is arranged in a force path of the fastening device 10 in order to detect a fastening variable in the form of a force, in particular a pretensioning force.

A perspective view of the measuring device 100 is shown in FIG. The measuring device 100 has a sensor unit 104 for detecting the fastening quantity by means of at least one sensor element 106. The sensor unit 104 is connected to an interface 108. The interface 108 is designed to provide an external readout device 1000 with the fastening size detected by the sensor unit 104. The interface 108 is exemplary designed as a contact interface. The interface 108 comprises four contact elements 110 which are arranged as contact surfaces 112 on an upper side of the measuring device 100. The upper side of the measuring device 100 faces the screw head or the nut 32 of the fastening device 10 in the fastened state. The interface 108 or the contact elements 110 can be contacted directly by the external readout device 1000 in order to exchange data or to transmit the fastening parameters. The interface 108 optionally includes a further contact element 114, which is provided for connection to a ground.

The interface 108 is connected to the sensor unit 104 via a connection element 116. The connecting element 116 is designed, for example, as electronics 118. The electronics 118 comprise an integrated circuit 120 which is connected to the sensor unit 104 and the interface 108. The electronics 118 also has a memory element 122 in which data, in particular the data or fastening variables detected by the sensor unit 104, can be stored. An ID of the measuring device 100, via which the measuring device can be identified / characterized, is additionally stored, for example, in the memory element 122.

The electronics 118 are supplied with energy via an energy supply unit 124. The energy supply unit 124 is designed to supply the sensor unit 104 or the sensor element 106 with energy. The energy supply unit 124 comprises an energy storage element 126 and an energy absorption element 128.

The energy absorption element 128 is designed to convert an external, in particular, electromagnetic signal for supplying energy to the measuring device 100 into electrical energy. In the embodiment according to FIG. Lb, the energy absorption element 128 is designed, for example, to convert an electromagnetic signal in the form of light. The energy absorption element 128 is designed in particular as a solar cell 130 which, by means of the photovoltaic effect, converts the light received, for example sunlight, into electrical energy. The energy absorbing element 128 is arranged on the surface of the measuring device 100. The energy absorption element 128 has an area of at least 0.5 cm ² , in particular at least 1 cm ² , preferably in a range between 2 cm ² and 10 cm ² . The size of the energy absorption element 128 is preferably designed such that it corresponds to at least 10%, preferably at least 25%, preferably at least 50%, of the area exposed in the fastened state of the fastening device 10. In the embodiment shown, the exposed surface is that part of the surface of the measuring device 100 facing away from the heavy-duty component 12 and which is not acted upon by the fastening device 10 by the nut 32. The energy absorption element 128 is preferably designed in such a way that it has a power of at least 100 pW, preferably at least 250 pW, preferably at least 1 mW. In this way, the energy storage element 126 can advantageously be charged sufficiently in a few seconds to supply the sensor unit 104 and / or the electronics 118 with energy.

The energy storage element 126 is designed, for example, as a capacitor in the form of a tantalum capacitor. Due to its internal porous structure, the tantalum capacitor advantageously has a very high storage capacity with a small size. The energy storage element 126 has, in particular, a capacity of at least 100 pF, preferably at least 0.5 mF, preferably several mF, in order to provide a sufficiently high energy for carrying out measurements or communication with the external readout device 1000. The energy supply unit 124 is designed, for example, in such a way that the energy is stored in the energy storage element 126 until a threshold value is reached, the sensor element 106 being activated when the threshold value is exceeded. The threshold value is, for example, a capacitance value of 50 pF. Alternatively, the threshold value can also be designed as a voltage on the energy storage element, such as 3.0 V.

The energy supply unit 124 is supplied with energy, for example, via an external energy supply unit 1100. The external power supply unit 1100 is exemplified as a flashlight 1102 with a lens system System designed to also illuminate remote measuring devices 100 or fastening devices 10. Alternatively, it would also be conceivable that the external energy supply unit 1100 is designed as a floodlight. The electromagnetic radiation emanating from the external energy supply unit 1100 is advantageously optimized for the solar cell 130 used, in which the emitted wavelength is adapted.

The sensor element 106 of the sensor unit 104 is designed, for example, as a passive sensor element 132. In particular, the sensor element 106 is designed as a shielded capacitor 134 and shown in Fig. Lc in a sectional view. The sensor element 106 comprises, for example, four electrically conductive planes 136 which are electrically isolated from one another by the base body 102 of the measuring device 100. For electrical insulation, the base body 102 can, for example, have a ceramic structure, a reinforced plastic or a glass fiber-reinforced plastic in the areas between the conductive planes 136. The conductive planes 136 are preferably made of a metal such as copper or a copper alloy.

It is also conceivable that the conductive planes 136 consist of gold or a gold alloy. The two outer conductive planes 138 are assigned to a shield 140. These outer planes 138 advantageously cover as large a proportion of the plane as possible, in particular at least 50%, preferably at least 75%, of the plane in order to provide effective shielding of the sensor element 106 from external interference factors such as electromagnetic radiation. The two outer levels 138 are electrically connected to one another via a shielding element 142, which is preferably arranged preferably completely along or near the outer edge of the conductive levels 136. Furthermore, the outer planes 138 are connected to the ground contact 114.

The two inner conductive planes 144 form a parallel plate capacitor. The conductive planes 136 of the parallel plate capacitor are ring-shaped and run circularly around the central opening 146 of the measuring device 100. The inner planes 144 are preferably arranged completely within the shield 140 in order to avoid interference with the detection of the fastening size. It is also conceivable that the sensor unit 104 has a plurality of sensor elements 106. For example, the sensor unit 104 could have three sensor elements, which are also designed as parallel-plate capacitors and are distributed around the central opening 146 in the manner of a segment of a circle.

Furthermore, the sensor unit 104 has a reference structure 148. The reference structure 148 also consists of a parallel-plate capacitor and is arranged completely within the shield 140. In contrast to the sensor element 106, the reference structure 148 is arranged outside the direct force path, so that the reference structure in the fastened state is not arranged directly below the screw head or the nut 32 of the fastening device 10.

The sensor element 106 and the reference structure 148 are each connected to a contact element 110 of the interface 108 in order to provide the detected fastening variable to an external readout device 1000. By means of the electronics 118 and / or the external readout device 1000, it is possible, for example, to determine a fastening force based on a difference between the two recorded fastening variables in the form of the capacitances. Furthermore, it is also possible that other influences, such as the temperature, the humidity, the aging of the carrier material or the workpiece, etc., can also be determined using the recorded fastening parameters.

In this embodiment, the capacitors or the sensor element 106 and the reference structure 148 are read out as soon as the energy supply unit 124 has stored enough energy or a threshold value is exceeded. The control takes place via the electronics 118, which are connected both to the energy supply unit 124 and to the sensor unit 104. Alternatively or in addition, it is also conceivable that the capacitors are read out at predetermined time intervals, for example once a day, weekly, monthly or annually. The recorded values are preferably provided digitally via the interface 108. The interface 108 designed as a contact interface can, for example, be connected to an external readout device 1000 designed as a handheld power tool 1004 for data exchange. The connection is made via a cable 1006, for example, which can be directly connected to the contact elements 110 of the measuring device. The handheld power tool 1004 is designed, for example, as a cordless screwdriver.

In addition, the interface 108 is designed to be connectable to an external communication unit 150. The external communication unit 150 is designed, for example, as an RFID tag 152 and can be connected to the measuring device 100 or the interface 108 via an integral connection, for example by gluing. In the state connected to the external communication unit 150, the detected fastening size can be provided to an external readout device 1000 such as a smartphone via wireless communication 1010. The RFID tag can be detuned at suitable frequencies, for example by the electronics 118, or the value of the fastening size can be read out and converted into digital information. A clearly user-friendly system can advantageously be implemented as a result. The connection between the measuring device 100 and the external communication unit 150 is preferably designed such that it is detachable, in particular detachable without tools. The external communication unit 150a is supplied with energy via the energy consumed by the energy supply unit 124.

Alternatively, it would also be conceivable for the external communication unit 150 to be designed as a SAW tag that enables wireless communication by means of surface waves.

An alternative embodiment of the measuring device 100 is shown in FIG. 2. The measuring device 100a essentially corresponds to the measuring device 100 described above and differs in the design of the interface 108a and the external communication unit 150a. The interface 108a is designed as a sensor node which has suitable contacts for connection to the external communication unit 150a, for example in the form of a Bluetooth beacon 154a. For the connection of the external communication unit 150a to the measuring device 100a, which can be detached without tools, the measuring device 100a has a mechanical interface 156a. The mechanical interface 156a is partially formed in one piece with the base body 102a of the measuring device 100a and comprises a plurality of latching arms 158a, which are designed for a non-positive and positive connection to a housing 160a of the external communication unit 150a. The latching arms 158a engage in corresponding recesses (not shown) on the outside of the housing 160 of the external communication unit 150a. The Bluetooth module of the external communication unit 150a is arranged on a printed circuit board within the housing 160 in order to protect this advantageously.

As in the previous exemplary embodiment, the external communication unit 150a is supplied with energy via the energy taken up by the energy supply unit 124a. As before, the energy supply unit 124a comprises an energy absorption element 128a and an energy storage element 126a.

The energy absorption element 124a is an example of the conversion of an electromagnetic signal in the form of a radio wave or a radio wave. The energy absorption element 128a is arranged on the surface of the measuring device 100a. The external energy supply unit 1100a can for example be designed as an RFID transmitter or as a GSM transmitter.

FIG. 3 shows a further alternative embodiment of the measuring device 100 in a perspective view. The measuring device 100b differs from the previously described measuring device 100 in particular in the design of the interface 108b. The interface 108b comprises two by four contact elements 110b in the form of plug sockets 162b, which are connected to the sensor unit 104b. There are four plug connectors each 162b is connected to the sensor element 106b and four plug connectors 162b are connected to the reference structure 148b. The plug connectors 162b are preferably designed as MMCX (micro-miniature coaxial) plug connectors. The plug connectors 162b are directed outwards in order to achieve the most compact possible construction of the measuring device 100b.

In FIGS. 4 to 9b, further embodiments of the measuring device 100 are shown in a schematic side view. The interfaces 108c to 108h are always designed as contact interfaces which can be connected to an external communication unit, not shown. Furthermore, all measuring devices 100c to 100h have an optional energy supply unit 124c to 124h.

The measuring device 100c according to FIG. 4 has a base body 102c which is integrally formed with the washer 36c of the fastening device 10. The measuring device 100c has a transmission element 164c, which is designed to convert a physical input variable in the form of a force that acts on the measuring device 100c in the fastened state starting from the fastening device 10, into a physical output variable. The transmission element 164c is designed, for example, as an elastic element 166c, which has a rubber-like sheath that is filled with a particularly viscous fluid. Alternatively, a fluid-filled balloon would also be conceivable. The elastic element 166c converts the physical input variable into a physical output variable in the form of a pressure and / or deformation or extended distance of the transmission element 164c. The physical output variable is detected by the sensor unit 104c of the measuring device 100c and provided as a fastening variable for the interface 108c. The sensor unit 104c is designed for this purpose, for example, to detect the pressure. This can be implemented, for example, in that the sensor unit 104c has a sensor element 106c in the form of a bridge circuit with four resistors, in particular only one or two of the resistors changing their value due to the bending or the pressure. Alternatively, the deformation could be detected, for example, by a sensor element 106c in the form of an optical sensor such as a camera. The measuring device 100d according to FIG. 5 has a base body 102d which is formed in one piece with the washer 36d of the fastening device 10. The measuring device 100d has a transmission element 164d which is designed to convert a physical input variable in the form of a force that acts on the measuring device 100c in the fastened state starting from the fastening device 10 into a physical output variable in the form of a light signal. The transmission element 164d is designed, for example, as a light-conducting layer 168d. Alternatively, a light guide embedded in a layer would also be conceivable. The light-conducting layer 168d converts the physical input variable or the pinching caused into a physical output variable in the form of light transmission through the transmission element 164d. In particular, the light-conducting layer 168d is designed in such a way that the light transmission through the transmission element 164d changes as a function of the force applied. The physical output variable is detected by the sensor unit 104d of the measuring device 100d and made available as a fastening variable for the interface 108d. The sensor unit 104d is designed for this purpose, for example, to detect the light transmission. This can be implemented, for example, in that the sensor unit 104d has a sensor element 106d in the form of an optical sensor such as a camera or a photodiode. In order to improve the measurement, a light signal can be introduced into the transparent transmission element 164d at one or more points via a light source (not shown).

The measuring device 100e according to FIG. 6 has a base body 102e which is formed in one piece with the washer 36e of the fastening device 10. The measuring device 100e has two transmission elements 164e which are designed to convert a physical input variable in the form of a force that acts on the measuring device 100e in the fastened state starting from the fastening device 10 into a physical output variable in the form of a magnetic field. One of the transmission elements 164e is designed as a magnetic element 170e for generating a magnetic field. The magnetic element can, for example, be designed as a permanent magnet 172e as mentioned. Alternatively, it would also be conceivable that the magnetic element 170e is designed, for example, as an electromagnet or a coil. The Transmission element 164e designed as a magnetic element 170e is arranged in such a way that the generated magnetic field is at least partially, preferably completely, with the force path of the fastening device 10 and / or the other transmission element 164e, which is designed as a layer 174e, which is based on the magnetic field influenced by the force acting on them and / or displaced, overlaps. The layer 174e can, for example, be designed as a ferromagnetic layer whose field conductivity is dependent on the pressure. Alternatively, it would also be conceivable that the layer 174e is designed as a ferromagnetic “Shape Memory Alloy” which changes its crystal configuration at a predefined pressure in such a way that it switches from magnetic field conducting to magnetic field displacing from this threshold value. Both quantitative measurements and reliable qualitative measurements can advantageously be carried out via the various layers 174e. The physical output variable is detected by the sensor unit 104e of the measuring device 100e and provided as a fastening variable for the interface 108e. For this purpose, the sensor unit 104e is designed, for example, to detect the magnetic field. This can be implemented, for example, in that the sensor unit 104e has a sensor element 106e in the form of a magnetic field sensor such as a Hall sensor. In order to improve the measurement, the sensor unit can have several Hall sensors.

The measuring device 100e according to FIG. 7 has a base body 102f which is formed in one piece with the washer 36f of the fastening device 10. The measuring device 100f has a transmission element 164f which are designed to convert a physical input variable in the form of a force that acts on the measuring device 100f in the fastened state from the fastening device 10 into a physical output variable in the form of an eddy current or an inductance . The transmission element 164f is designed as a coil 176f for inducing an eddy current in the fastening device 10. Depending on the force coupling of the fastening device 10, the response signal and thus the physical output variable, which is measured by the sensor unit 104f, changes. The sensor element 106f can include the excitation coil 176f. The force coupling of the fastening device 10 results from the forces acting between the individual parts, for example the nut 32 and the measuring device 100f. The measuring device 100g according to FIG. 8 has a base body 102g which is constructed in one piece with the washer 36g of the fastening device 10. The measuring device 100g has a transmission element 164g which is designed to convert a physical input variable in the form of a force, which in the fastened state acts on the measuring device 100g from the fastening device 10, into a physical output variable. The sensor unit 104g comprises a sensor element 106g, which is designed as a passive sensor element. For example, the sensor element 106g is designed to detect a fastening variable in the form of a force. The sensor element 106g can be used, for example, as a capacitor that detects the attachment size via a change in resistance. The transmission element 164g is designed as a reinforcement layer 176g which is electrically conductive and, by means of suitable structures, amplifies a change in the resistance of the sensor element 106g as a function of pressure. Alternatively, it would also be conceivable that in a different configuration of the sensor unit 104g or the sensor element 106g, the transmission element 164g or the reinforcement element 176g is designed differently. For example, it would also be conceivable that the reinforcement element 176g amplifies the change in a current as a function of the applied force.

The measuring device 100h according to FIG. 9a has a base body 102h which is constructed in one piece with the washer 36h of the fastening device 10. As in the previous embodiments, the measuring device 100h has a sensor unit 104h, an energy supply unit 124h and an interface 108h. Furthermore, the measuring device 100h or the sensor unit 104h has an excitation element 180h for mechanical and / or electrical excitation of the fastening device 10 and a sensor element 106h, where the sensor element 106h is designed to determine an attachment variable depending on the response to the excitation capture. The excitation element 180h is designed, for example, as a piezo element 182h. The excitation element 180h is preferably arranged on a side of the measuring device 100h or the washer 36h facing the component 12 to be fastened. The piezo element 182h can be designed as a layer or coating or as a disk. By applying an electrical voltage or AC voltage can be used to generate a force or a vibration to excite the fastening device 10, the heavy-duty component 12 and / or the workpiece 18 by means of the excitation element and be coupled into the force path. The excitation element 180h can be formed at least partially in one piece with the sensor element 106h, so that the detection of the fastening variable also takes place at least partially via the piezo element 182h. At the same time as the excitation, the capacitance can be measured, or the restoring force can be recorded electrically as a current pulse with a time delay, from which conclusions can be drawn about the fastening system. Depending on the dynamic stimulation, conclusions can also be drawn from the surrounding fastening matrix, for example through resonances and / or reflections of mechanical vibrations.

Alternatively or additionally, it is conceivable that the excitation element 180h is designed to carry out an impedance measurement. For this purpose, the excitation element 180h can be designed, for example, as a capacitor, the voltage in the capacitor being recharged at different frequencies and radiating into the fastening matrix or the fastening device 10 and the workpiece 18. A sensor element 106h detects a fastening variable through the response, that is, the speeds of the charge reversal, for example by means of a frequency or phase shift, the system capacitor and the environment. This allows conclusions to be drawn about existing ions, cavities or also cracks in the environment.

In Fig. 9b is a system of two measuring devices 100h, which are each verbun with a fastening device 10 for fastening a heavy-duty component 12 are shown in a schematic side view. The excitation element 180h can also be used as an impact or sound generator. It is also conceivable that the excitation element 180h of the one measuring device 100h is used to measure the impedance of the further measuring device 100h. Advantageously, the two measuring devices 100h or the interfaces 108h of the measuring devices 100h are each connected to an external communication unit as described above, so that the measuring device 100h can wirelessly communicate with one another and exchange data with one another.

Claims

Expectations

1. Measuring device for a fastening device (10), with a base body (102), with a sensor unit (104), which is designed to detect at least one fastening quantity, with an interface (108) that communicates with the sensor unit (104) is connected and designed to provide at least one attachment size to an external readout device (1000), characterized in that the interface (108) can be electrically connected to a wireless communication unit (150) or directly to the external readout device (1000).

2. Measuring device according to claim 1, characterized in that the sensor unit (104) has a passive sensor element.

3. Measuring device according to one of the preceding claims, characterized in that the sensor unit (104) has a transmission element (164c) which is designed to convert a physical input variable into a physical output variable, the attachment variable based on the physical rule Output variable is detected by the sensor element (106).

4. Measuring device according to claim 3, characterized in that the transmission element (164c) is designed to be elastic in such a way that the fastening size can be detected via a deformation of the transmission element (164c).

5. Measuring device according to one of claims 3 or 4, characterized in that the transmission element (164d) is designed such that at least one optical property of the transmission element (164d) changes as a function of the physical input variable.

6. Measuring device according to one of claims 3 to 5, characterized in that the transmission element (164e) is designed such that at least one magnetic property changes as a function of the physical input variable.

7. Measuring device according to one of claims 3 to 6, characterized in that the transmission element (164g) is designed such that at least one electrical property changes as a function of the physical input variable.

8. Measuring device according to one of the preceding claims, characterized in that the interface (108) has at least one mechanical connection element for non-positive and / or positive connection with the wireless communication unit (150).

9. Measuring device according to one of the preceding claims, characterized in that the sensor unit (104) and the interface (108) are arranged at a distance from one another, the sensor element (106) being arranged radially inward and the interface (108) being arranged radially outward.

10. Measuring device according to one of the preceding claims, characterized in that the interface (108) is connected to the sensor element (106) via an electric connecting element.

11. Measuring device according to one of the preceding claims, characterized in that the measuring device (100) has a shield (140) which is designed to shield the sensor element (106) and / or the connecting element.

12. Measuring device according to one of the preceding claims, characterized in that the measuring device (100) has a reference structure (148) in particular for comparison with environmental parameters.

13. Measuring device according to one of the preceding claims, characterized in that the interface (108) has at least two contact elements (110), which are each designed to provide at least one fastening size.

14. Measuring device according to one of the preceding claims, characterized in that the base body (102) is designed as an annular disc, as a Lei terplatte, as a nut (32) or as a washer (36).

15. System comprising a measuring device (100) according to one of the preceding claims and a wireless communication unit (150), wherein the wireless communication unit (150) is connected to the measuring device (100) in a materially or non-positively and / or form-fitting manner.