DE19912837C2 - Torque wrench - Google Patents

Abstract

A signal is transmitted by a wrench force sensor (42) and a workpiece identification device (36) generates an identification signal, both of these signals being sent to a control device (40). The wrench force signal is compared in the control device with at least one pre-determined or pre-determinable reference signal, and then based on the information from the wrench force and identification signals, the device generates a screw force control signal. An Independent claim is also included for the testing method using this wrench.

Description

The invention relates to a torque wrench for testing a torque elements during a screwing process on a workpiece and a method for Testing a torque as defined in the respective claims 1 and 16 are described.

In order to check the tightening torque of a screw connection, torque wrenches are conventionally used. Such torque wrenches allow on the one hand a check whether the tightening torque is equal or greater than a predetermined reference torque and, on the other hand, should not be the case until the reference torque is reached continue to attract. In particular, there are so-called kink keys Use where the torque introduced by a mechanism is limited and the user can hear and feel the achievement of Reference torque is displayed. Here, the reference torque, at which the kink key triggers, factory-set.

Are such conventional torque wrenches in the assembly or Manufacturing technology used, however, serious problems arise that in a lack of security against incorrect operation as well as in an egg restricted area of application. This is how these torque wrenches support the user prior to starting a torque test, not whether the key is suitable for this at all, with which the user switches to a manual and error-prone control is forced using a checklist. When a Large number of screw connections to be checked, the user must carry out the check Also log the results manually and make sure that there is no test was ignored. This is particularly problematic when screw connections with different reference torques should be checked, because here the torque wrench used must also be recorded.  

DE 197 08 667 A1 discloses a method and a device for testing Torques of screw connections, power screwdrivers and mechanical Torque wrenches. An electronic torque wrench with measuring sensor in the screw axis allows direct testing of mechanical Torque wrenches, as well as by fastening a screw simulator Fixing points of the device for testing motorized power wrenches.

DE 296 15 123 U1 discloses an electronic measuring key, the middle part of which contains an electronic circuit with an EEPROM. The parameters of Measurement programs can be stored in the EEPROM and are up to one Change automatically using input means each time the measuring program is called callable.

DE 34 29 950 C2 describes a torque wrench with a Strain gauge bridge. The strain gauge bridge is with an electronic Evaluation unit connected to a microprocessor and a display device and arranged such that the torque wrench has an extended measuring range having.

DE 32 21 658 A1 discloses a method and an apparatus for checking the Tightening torque of screws and the like. It is suggested, the onset of rotation by a torque-dependent activated angle encoder of the screws and in uniform angular increments to measure and save the associated torques. By representing the entire torque curve and an evaluation using a Microprocessor can get rid of the randomness of breakaway torque Statement about the tightening torque can be obtained.  

It is an object of the invention to provide a torque wrench for testing a To provide torque on a workpiece, the improved error i Has safety and simple operating properties and preferably in simple way for torque tests with different reference torques can be used. It is also an object of the invention to specify the appropriate procedure for torque testing.

This task is accomplished using a torque wrench as well as a procedure the features specified in claim 1 and claim 16 solved. Before drawn embodiments are the subject of the dependent claims.

According to the invention comprises a torque wrench for checking a torque during a screwing operation on a workpiece

• A torque sensor for outputting a torque signal,
• - A workpiece identification device for generating an identification tion signal, which is assigned to the respective workpieces, and
• - A control device with the torque sensor and the factory piece identification device is in signal connection,

the control device for a comparison of the torque signal with at least one predetermined or predeterminable reference torque signal and to generate a screw connection control signal based on ge of the identification signal and the torque signal comparison is designed.

This advantageously results in a high level of error and operational reliability Test of tightening torques of screw connections reached and at the same time the prerequisites for simple, automated logging of test results created. So includes the tightening control signal advantageously the result of the torque test process, i. H. the result nis whether the reference torque has been reached, while the tested Workpiece, e.g. B. its serial or part number is identifiable.

According to a preferred embodiment, the torque wrench comprises a signal output device for outputting the screw control signal  and the identification signal to one of the torque wrenches spatially Separately provided signal receiving device with the control device is in signal connection and is preferably a non-contact electro designed for magnetic signal transmission. This makes it more advantageous show the result of every single torque test of the workpiece transmitted to the external signal receiving device by radio and thus allows a particularly simple and fail-safe monitoring and logging of the Checking processes with the torque wrench.

According to a further preferred embodiment, the torque signal, the reference torque signal and the screw connection control signal electrical, magnetic or electromagnetic signals and control direction is a microprocessor computer. It is also an exclusively mecha African processing and comparison of the torques as well as output of the signals possible, but advantageously from cost and functionality establish electrical or electronic components.

According to a further preferred embodiment, the signal output is on direction an electromagnetic transmitter. This can be play for example a radio transmitter that is in a generally released Frequency band (e.g. at 27 MHz, 433 MHz) the signals to an external reception device sends. This has the advantage that no disturbing electrical Cables for external signal transmission are necessary.

According to a further preferred embodiment, the workpiece identification is tion device a code reader, in particular a bar or bar code reader. In particular, the workpiece identification device can recognize a pattern be predetermined means in a more unambiguous Way can assign a workpiece. However, it is also possible to electro African transponder systems to use, preferably those that are non-contact can be read out electromagnetically.

According to a further preferred embodiment, the torque  break a kink bar function, the torque sensor to one a permanent magnet attached to a torque rod or buckling rod and a magnetic switch, in particular a reed switch or an inductor tion switch and the magnetic switch for detecting an offset of the Permanent magnets when the torque rod kinks due to a Reaching a predetermined reference torque relative to the magnet switch is formed. This makes it possible in a particularly simple manner to generate electrical torque signal, which the reaching of the Refe limit torque. At the same time, the advantages of a kink wrench maintained, especially the clearly audible and noticeable triggering as soon as that Reference torque is reached.

According to a further preferred embodiment, the torque sensor a strain gauge sensor, preferably in the form of a strain gauge bridge, which is based on an initiated torque by bending responding torque rod of the torque wrench is arranged. The The torque rod is thus designed as a bending rod. Through the verbie The torque rod undergoes a change in the geometry of the strain gauge streak, which results in a change in resistance. Advantageously can any such change in resistance by means of the control device in a clearly the size of the corresponding initiated torque be assigned.

According to a further particularly preferred embodiment, one is a tool holder of the torque wrench opposite end the torque rod, a locking device arranged which the Torque bar unlocks when it receives an unlock signal from the control facility receives. This allows with a single torque wrench sel screw connections with different assigned in a simple manner Check reference torques without a complex mechanical new to have to set a trigger torque setting.

According to a further preferred embodiment, the locking comprises  device a ferromagnetic enclosed by a magnetic coil Locking bolt, which in a locking recess in the torque ment rod for locking it can be inserted, and by means of a current The magnetic coil can be struck out of it. This makes it possible advantageously, a kink key function of the torque wrench in easy to combine with different reference torques.

According to a further preferred embodiment, the torque comprises key a control signal receiving device, which with the control device in Signal connection is established and to receive control signals from an external Control device is designed, preferably by non-contact electro magnetic transmission. This advantageously enables bidirectional Signal transmission between the torque wrench and the external control device, making the torque wrench more efficient and flexible to use is cash. In particular, the control signals of the external control device be dependent on the identification signal and for example one for the Workpiece individually adjusted reference torque signal included.

According to the invention, a method for testing a torque during a screwing process on a workpiece, in particular using a device according to the invention, comprises the following steps in this sequence:

• a) detecting a workpiece or a workpiece identification, in particular a corresponding code, preferably a barcode;
• b) generating an identification signal corresponding to the workpiece;
• c) Checking the torque of the screw connection of the workpiece and generation against a corresponding torque signal;
• d) comparing the torque signal with a predetermined or before determinable reference torque signal;
• e) generating a tightening control signal based on the identifi Ornamental signal and the torque signal comparison.

The screw connection control signal contains all necessary essentials Data of a torque test of a screw connection and thus enables  advantageously a fail-safe and reliable test of tightening torque complex workpieces. In particular, the screw con troll signal the torque test result, d. H. the result whether the Refe limit torque was reached.

According to a preferred embodiment of the method, this includes inventions method according to the following step of the output of the screw Exercise control signal to a receiving device, preferably by a non-contact electromagnetic transmission. This makes it easy Monitoring and logging of torque testing processes by a external monitoring and control device possible, which leads to another Increases error and operational safety.

According to a further preferred embodiment of the method immediately after step (b) the identification signal is received direction issued, preferably by a non-contact electromagnetic cal transfer. This allows before the actual torque test step is started, a preliminary check is advantageously carried out to determine whether this workpiece is to be tested at all and which test parameters note.

According to a further preferred embodiment of the method, the Reference torque signal depending on the generated identification signal, if necessary after reconfirmation by the receiving facility, fixed. This advantageously enables the identified workpiece automatically assign the corresponding reference torque, preferably without the user going back to test and parameter lists must grab.

The invention is illustrated below by way of example based on a preferred embodiment shapes described with accompanying drawings. It shows:

Figure 1 is a schematic sectional view of a first embodiment of a torque wrench according to the invention. and

Fig. 2 is a schematic sectional view of a second embodiment of a torque wrench according to the invention.

In a simplified, schematic sectional side view, a first embodiment of a torque wrench according to the invention is shown in FIG. 1. The torque wrench 10 comprises a housing body 12 which has an integrally formed handle 14 at its rear end. In the area of the handle 14 , a battery recess is provided in the housing body 12 for receiving a battery 16 , which can be inserted into the housing body 12 in the longitudinal direction from the rear end. The battery recess is closed by a battery cover 18 which is attached to a rear end face 17 of the housing body 12 .

At one of the rear end face 17 in the longitudinal direction of the housing body 12 opposite end, a torque rod bushing 20 is provided in the housing body 12 through which a torque rod 22 is partially inserted into a torque rod recess 24 . At a extending in the longitudinal direction from the housing body 12 end of the torque rod 22 , a tool holder head 25 is provided for arranging a nut, which is designed as a 90 ° ratchet head. The torque rod 22 has in the area of the torque rod guide 20 a pivot pin bore which extends perpendicular to the longitudinal axis of the torque rod 22 parallel to the plane of the drawing. A pivot pin 26 is inserted through the pivot pin bore, the ends of which are fixed in the housing body 12 and which pivotally supports the torque rod 22 .

Between a rear end face 28 of the torque rod 22 and a trigger torque setting 30 , a spring 32 is arranged, which acts on the torque rod 22 with a longitudinal spring force. The size of the spring preload can be adjusted by the triggering torque setting 30 by a spring contact surface 34 of the triggering torque setting 30 being displaced in the longitudinal direction in order to control the compression of the spring 32 , which is indicated by the arrow x. To do this, the battery cover 18 and the battery 17 must be removed in order to gain access to the rear side of the triggering torque setting. The amount of spring bias determines the reference torque of the torque wrench 10 , ie the torque at which the key is triggered by a "kink". The triggering or kinking occurs precisely when a kinking force predetermined by the reference torque in the key 10 is achieved by a torque introduced into a screw connection to be tested. The buckling force, which is normal to the longitudinal axis of the torque rod 22 and to the plane of the drawing, acts on the rear end face 28 of the torque rod 22 . The spring 32 can compensate for forces which are smaller than this predetermined buckling force. However, if the amount of buckling force is reached, the torque rod 22 is jerkily pivoted in the torque rod recess 24 until an edge of the rear end face 28 touches the inner surface of the torque rod recess 24 . Typically, the offset of the rear face 28 is about 3-4 mm. This triggering of the torque wrench 10 is accompanied by an audible and perceptible kinking noise.

According to the invention on an outer surface of the housing body 12 on the handle 14 opposite in the longitudinal direction side a as a workpiece identification means serving barcode reader 36, as Signalausga striking direction serving radio transmitter 38 and a serving as the controller microprocessor computer 40 arranged side by side, with each other and the battery 16 are electrically connected. The bar code reader 36 is directed such that its preferred readout direction runs parallel to the longitudinal axis of the torque rod 22 and the housing body 12 and is directed forward in the direction of the tool holder head 25 . The detected Raumwin angle of the bar code reader 36 is shown schematically by the beam.

Furthermore, a reed switch 42 serving as a magnetic switch is arranged on the outside of the housing body 12 . On the torque rod 22 , a hard magnet 44 is fastened in such a way that it faces the reed switch opposite, ie lies on a line which runs from the longitudinal axis of the torque rod to the reed switch 42 . The reed switch 42 is electrically connected to the microprocessor computer.

The following is the operation and operation of the torque wrench according to the first embodiment of the invention:

First, the worker or user reads in a barcode of a workpiece (not shown) by means of the barcode reader 36 . The barcode can contain, for example, the serial or part number of the workpiece. The so Won nene identification signal of the to be tested workpiece is subsequently relayed as an electronic signal to the microprocessor computer 40 to be processed there to eventually.

Subsequently, the possibly further processed identification signal is transmitted electrically to the radio transmitter 38 , which then sends this to a signal reception device, not shown, which is provided separately from the torque wrench and is provided as an electromagnetic signal without contact. The freely accessible frequency ranges at 27 MHz and 433 MHz are particularly suitable as transmission frequencies. The signal receiving device is in signal connection with an external control device (not shown) which evaluates and stores the identification signal. If the transmitted identification signal corresponds to a predetermined signal stored in the external control device, the torque wrench 10 used by the user is suitable for checking predetermined screw connections of the identified workpiece. In this case, the torque test is released, which is indicated to the user by an acoustic and / or visual signal. The display can be done by a display device (not shown) which is connected to the external control device.

Alternatively, the acoustic and / or optical enable signal can also be provided in the torque wrench by a device (not shown) provided for this purpose (for example an LED and an acoustic buzzer). In this case, the radio transmitter 38 must also include a radio receiver (control signal receiving device, not shown) so as to permit bidirectional contact-free data transmission between the torque wrench 10 and the external signal receiving device. To trigger the release, the external control device sends a corresponding release signal to the radio receiver of the torque wrench. This signal is forwarded to the micro processor computer 40 , which then triggers the (not shown) release device of the torque wrench.

After approval has been given, the user starts checking the tightening torque of the first predetermined screw connection of the workpiece using the torque wrench 10 in the usual manner. When the predetermined reference torque is reached, the torque wrench "kinks", ie the torque rod or articulated rod experiences a jerky pivoting as described above. This pivoting has the consequence that the hard magnet 44 is displaced with respect to the reed switch 42 , with which the latter is actuated. The reed switch 42 thus functions together with the hard magnet 44 as a torque sensor and supplies a torque signal that is transmitted to the microprocessor computer 40 .

If a torque signal of the reed switch 42 is received by the microprocessor computer 40 , the predetermined reference torque has been reached and the screw connection has been successfully checked. The microprocessor computer 40 then causes the radio transmitter 38 to send a screw control signal to the signal receiving device. This signal is evaluated and stored by the external control device.

Not all predetermined screws are in the workpiece to be tested connections checked, the external control device can be a corresponding Output warning or error signal and possibly in addition to rework prompt. Because the result of each tightening operation is automatic in this way is logged and checked for each workpiece to be checked, a high  Failure safety achieved. If not all predetermined test procedures are successful completed, there is no release of the workpiece.

Fig. 2 is a schematic side sectional view of a second particularly preferred embodiment of the torque wrench according to the invention. Compared to the first embodiment shown in FIG. 1, the same or similar features have the same reference numerals and are not described again below.

On the rear end face 28 of the torque rod 22 , a locking body 52 is fixed with a locking recess 54 such that the longitudinal axis of the torque rod 28 coincides with the central axis of the circular cylindrical locking recess 54 . In the locking recess 54 is a circular cylindrical locking pin 56, whose outer diameter corresponds approximately to the inner diameter of the locking recess 54, can be inserted. The central axis of the locking bolt 56 coincides with the longitudinal axis of the torque rod 22 when no torque is being introduced. The locking bolt 56 is preferably ferromagnetic.

A section of the locking bolt 56 facing away from the locking body 52 is surrounded by a magnetic coil 58 which has an inner diameter which speaks approximately to the outer diameter of the locking bolt 56 . The solenoid 58 is arranged in the housing body 12 such that its longitudinal axis coincides with the longitudinal axes of the locking bolt 56 and the torque rod 22 if no torque is introduced. A return spring 60 is arranged between the rear end face of the locking bolt 56 and a spring abutment wall 62 of the magnetic coil 58 such that it exerts a longitudinal restoring force on the locking bolt 56 in the direction of the locking recess 54 . The locking body 52 , locking bolt 56 , solenoid 58 , return spring 60 and spring contact wall 62 together form a locking device 64 , the operation of which will be described later.

On the torque rod 22 , which is designed as a bending rod, strain gauges 66 are attached such that an operational bending of the torque rod 22 by a torque introduced into the torque wrench 50 leads to a change in the electrical resistance of the strain gauges 66 . In order to be able to rule out secondary influences, in particular temperature influences, on the resistance of the strain gauges 66 , these are electrically connected in a bridge circuit. The output of the strain gauge bridge 66 is electrically connected to the microprocessor computer 40 via connecting lines. In the microprocessor computer 40 , a calibration function is stored, by means of which measured strain gauge strip resistances can be uniquely assigned to the sizes of the torque introduced into the torque wrench 50 .

The mode of operation of the second embodiment of the invention is described below, only the differences from the mode of operation of the torque wrench 10 shown in FIG. 1 being discussed. After the identification signal has been sent by the radio transmitter 38 functioning as the signal output device to the external signal receiving device and the further processing in the external control device, the external control device sends control signals to the torque wrench 50 when the test is released. These control signals are received by the radio receiver 68 serving as a control signal receiving device and include a triggering torque setting signal which serves to set the reference torque. The release signal is preferably also transmitted to the torque wrench.

The received control signals are forwarded to the microprocessor computer 40 as electrical signals. After the user has perceived the release signal, for example by lighting up an LED, not shown, on the outside of the housing body 12 , he applies the torque wrench 50 to the screw connection of the workpiece to be tested and begins with the testing of the tightening torque. The torque thus introduced into the key leads to a bending of the torque rod 22 , which is detected by the strain gauge bridge 66 . As described above, the microprocessor can uniquely assign a torque to such a bend.

The torque signal thus obtained is compared with the reference torque signal obtained from the trigger torque setting signal previously received. If the torque signal is equal to or greater than this reference torque signal, the torque rod 22 is triggered by the locking device 64 by outputting an unlocking signal, whereupon the torque wrench 50 "kinks". For this purpose, the microprocessor computer 40 controls the energization of the solenoid 58 in such a way that the locking bolt 56 is retracted longitudinally in the direction of the spring 60 in order to disengage from the locking recess 54 . This allows the torque rod 22 to pivot about the pivot pin 26 until the locking body 52 strikes the inner wall of the housing body 12 . The user perceives this "kinking" of the torque wrench 50 audibly and noticeably.

If the torque wrench 50 is further rotated after the locking device 64 has been triggered in order to further increase the tightening torque, this undesirable increase can be determined by the strain gauge bridge 66 in conjunction with the microprocessor computer 40 . If the measured torque reaches the amount of a second reference torque, which is greater than the first reference torque, the microprocessor computer generates an error signal.

After completion of the torque test process of each predetermined screw connection, the radio transmitter 38 sends a screw control signal generated by the microprocessor computer 40 to the external signal receiving device. The screw connection control signal contains the measured value of the tightening torque reached and possibly the error signal if the torque test was not successfully completed. The external control device stores the bolting control signal and evaluates it and accordingly initiates rework or outputs an enable signal of the bolting process.

Instead of the locking device 64 described with reference to FIG. 2, other devices can also be used. It is thus possible, in particular if the buckling rod function of the torque wrench can be dispensed with, to permanently fix the rear end of the torque rod 22 in the housing body 12 . The feedback to the user that the reference torque has been reached can then be given by an optical and / or acoustic display. Furthermore, a vibration generator can also be integrated into the handle 14 , which generates a clearly perceptible mechanical signal as soon as the reference torque is reached.

Reference list

10th

Torque wrench

12th

Housing body

14

Handle

16

battery

17th

rear end face of the housing body

18th

Battery cover

20th

Torque bar bushing

22

Torque rod

24th

Torque rod recess

25th

Tool holder head

26

Swivel pin

28

rear face of the torque rod

30th

Tripping torque setting

32

feather

34

Spring contact surface of the tripping torque setting

36

Barcode reader

38

Radio transmitter

40

Microprocessor computer

42

Reed switch (torque sensor)

44

Hard magnet

50

Torque wrench (

2nd

, Embodiment)

52

Locking body

54

Locking recess

56

Locking bolt

58

Solenoid

60

Return spring

62

Spring system wall

64

Locking device

66

Strain gauge bridge (torque sensor)

68

Radio receiver

Claims (22)

1. Torque wrench ( 10 ; 50 ) for testing a torque during a screwing process on a workpiece

• - a torque sensor ( 42 ; 66 ) for outputting a torque signal,
• - A workpiece identification device for generating an identification signal, which is assigned to the respective workpieces, and
• a control device which is in signal connection with the torque sensor ( 42 ; 66 ) and the workpiece identification device,

wherein the control device is designed to compare the torque signal with at least one predetermined or predeterminable reference torque signal and to generate a screw connection control signal based on the identification signal and the torque signal comparison. 2. Torque wrench ( 10 ; 50 ) according to claim 1 with a signal output device for outputting the screw connection control signal and the identification signal to a signal receiving device which is spatially separated from the torque wrench ( 10 ; 50 ) and is in signal connection with the control device. 3. Torque wrench ( 10 ; 50 ) according to claim 2, wherein the Signalemp catch device is designed for a non-contact electromagnetic signal transmission. 4. Torque wrench ( 10 ; 50 ) according to claim 1 or 2, wherein the torque signal, the reference torque signal and the screw control signal are electrical, magnetic or electromagnetic signals and the control device is a microprocessor computer ( 40 ). 5. Torque wrench ( 10 ; 50 ) according to one of the preceding claims, wherein the signal output device is an electromagnetic transmission device ( 38 ). 6. Torque wrench ( 10 ; 50 ) according to one of the preceding claims, wherein the workpiece identification device is a code reader. 7. Torque wrench ( 10 ; 50 ) according to claim 6, wherein the workpiece diagnosis device is a bar code reader ( 36 ). 8. Torque wrench ( 10 ) according to one of the preceding claims with a buckling rod function, wherein the torque sensor ( 42 ) has a on a torque rod ( 22 ) attached permanent magnet ( 44 ) and a magnetic switch and the magnetic switch for detecting a Ver set of the permanent magnet ( 44 ) Bending the torque rod ( 22 ) due to reaching a predetermined reference torque is formed relative to the magnetic switch. 9. torque wrench ( 10 ) according to claim 8, wherein the magnetic switch is a reed switch ( 42 ) or an induction switch. 10. Torque wrench ( 50 ) according to one of claims 1 to 7, wherein the torque sensor is a strain gauge sensor which is arranged on a torque rod ( 22 ) of the torque wrench ( 50 ) which reacts to an initiated torque by bending. 11. Torque wrench ( 50 ) according to claim 10, wherein the torque sensor is designed as a strain gauge bridge ( 66 ). 12. Torque wrench ( 50 ) according to claim 10 or 11, wherein on a tool holder ( 25 ) of the torque wrench ( 50 ) opposite end of the torque rod ( 22 ), a locking device ( 64 ) is arranged, which ent the torque rod ( 22 ) locks when it receives an unlock signal from the control device. 13. Torque wrench ( 50 ) according to claim 12, wherein the locking device ( 64 ) comprises a magnetic coil ( 58 ) enclosed ferro-magnetic locking bolt ( 56 ) which in a locking recess ( 54 ) in the torque rod ( 22 ) for locking them tion is insertable, and by means of a current application to the magnetic coil ( 58 ) can be removed from this. 14. Torque wrench ( 10 ; 50 ) according to one of the preceding claims, wherein the torque wrench ( 10 ; 50 ) comprises a control signal control device which is in signal connection with the control device and is designed to receive control signals from an external control device. 15. Torque wrench ( 10 ; 50 ) according to claim 14, wherein the signal connec tion takes place by non-contact electromagnetic transmission. 16. A method for testing a torque during a screwing process on a workpiece, in particular using a device according to claims 1 to 15, with the following steps in this order:

• a) detecting a workpiece identification located on the workpiece;
• b) generating an identification signal corresponding to the workpiece;
• c) checking the torque of the screw connection of the workpiece and generating a corresponding torque signal;
• d) comparing the torque signal with a predetermined or predeterminable reference torque signal;
• e) generating a tightening control signal based on the identification signal and the torque signal comparison.

17. The method of claim 16, wherein the workpiece identification Barcode is. 18. The method according to claim 16 with the subsequent step of output of the screw connection control signal to a receiving device. 19. The method according to claims 16 to 18, wherein immediately after the Step (b) the identification signal to a receiving device will give. 20. The method according to claims 18 and 19, wherein the signal connection to the receiving device through a non-contact electromagnetic Transfer takes place. 21. The method according to claims 16 to 20, wherein the reference torque ment signal depending on the generated identification signal becomes. 22. The method of claim 21, wherein the reference torque signal after Confirmation is determined by the receiving facility.