CN109563711B

CN109563711B - Method for calibrating and/or operating a hand-held power tool and hand-held power tool

Info

Publication number: CN109563711B
Application number: CN201780048491.9A
Authority: CN
Inventors: C·H·梁; S·W·吴; M·施图姆; S·施文德; C·W·亚普; B·丹凯移
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2016-08-09
Filing date: 2017-07-06
Publication date: 2022-03-11
Anticipated expiration: 2037-07-06
Also published as: DE102017209040A1; CN109563711A; WO2018028897A1; EP3497292B1; EP3497292A1

Abstract

The invention relates to a method for calibrating and/or operating a hand-held power tool (10) which is provided for twisting at least one object (12) to be twisted. The invention proposes at least one test step (14) in which a test object corresponding to the object (12) to be twisted is twisted at least to such an extent that the test object is damaged by the twisting.

Description

Method for calibrating and/or operating a hand-held power tool and hand-held power tool

Background

A method for calibrating a hand-held power tool is known from US 2009/0090428 a1, by which damage to the object to be twisted is avoided.

Disclosure of Invention

The invention relates to a method for calibrating and/or operating a hand-held power tool, in particular a reinforcement bar (reinforcing bar) strapping apparatus, which is provided for twisting at least one object to be twisted.

It is proposed that the method comprises at least one test step in which a test object corresponding to the object to be twisted is twisted at least to such an extent that the test object is damaged by the twisting. The efficiency, in particular the cost efficiency, of the hand-held power tool can thereby be advantageously improved. In particular, the hand-held power tool can be adapted to different objects to be rotated by means of a method for calibration and/or operation. In addition, costs can be saved, since objects to be twisted can be used which are made of different and in particular particularly low-cost materials and/or smaller material thicknesses. The operational reliability can be increased particularly advantageously, since in particular uncontrolled incorrect operation leading to uncontrolled damage to the object to be twisted can be avoided.

A "hand-held power tool" is to be understood to mean, in particular, a portable power tool which is provided for being guided and advantageously held by a hand at least partially, preferably at least largely and particularly preferably completely, at least in one operating state. The term "at least a major portion" is to be understood here to mean, in particular, at least 55%, advantageously at least 65%, preferably at least 75%, particularly preferably at least 85% and particularly advantageously at least 95%. Preferably, the hand-held power tool is designed as a portable power tool. A "portable power tool" is to be understood here to mean, in particular, a power tool for machining workpieces, which can be transported by an operator without a transport machine. The portable power tool has a mass of less than 40kg, preferably less than 10kg, particularly preferably less than 5 kg. The hand-held power tool can be designed, in particular, as an electric drill, a hammer drill, a saw, a plane, a screwdriver, a milling machine, a sander, an angle grinder, a garden appliance, and/or a multi-function power tool. In a particularly preferred manner, the hand-held power tool is designed as a reinforcement strapping apparatus, which is provided in particular for connecting a reinforcement by means of an object to be twisted, in particular a wire (wire).

"provided" is to be understood in particular to mean specially programmed, designed and/or equipped. An object is provided for a specific function, in particular it is to be understood that the object fulfills and/or implements the specific function in at least one application and/or operating state.

In particular, the hand-held power tool comprises at least one drive unit, which is preferably provided for at least twisting the object to be twisted. A "drive unit" is to be understood to mean, in particular, a unit which is provided as a drive for at least one unit, preferably a plurality of further units. Preferably, the drive unit has at least one first drive direction and a second drive direction which is different from the first drive direction, wherein the drive unit is provided for driving different further units of the hand-held power tool depending on the drive direction. The drive unit preferably comprises at least one electric motor unit.

The hand-held power tool has a twisting unit, which is driven by a drive unit in particular in a second drive direction and by means of which the drive unit twists the object to be twisted. The hand-held power tool further comprises, in particular, a control unit, which is provided for actuating at least the drive unit in at least one operating state. The control unit is provided, in particular, in at least one calibration operating state and/or normal operating state of the hand-held power tool, for carrying out a method for calibration and/or operation. A "control unit" is to be understood to mean, in particular, a unit having at least one control electronics, and a "control unit" is to be understood, in particular, a unit having at least one processor unit and at least one memory unit, and preferably having an operating program stored in the memory unit, which operating program can be implemented, in particular, at least by means of the processor unit. Preferably, the operating program comprises a method for calibration.

A "method for calibrating and/or operating" is to be understood to mean, in particular, a method that can be carried out, preferably at least by means of a control unit, and is advantageously automated, which method is provided for calibrating and/or operating a hand-held power tool. The method for calibrating and/or operating is provided in particular for adapting a hand-held power tool to at least one object to be twisted, and preferably to a plurality of, in particular differently configured, objects to be twisted. The calibration and/or operation of the hand-held power tool is dependent in particular on at least one object parameter, which preferably characterizes the object to be twisted and can be changed in particular during standby and/or operation. The object parameters are in particular the shape, preferably the thickness, the temperature, the type of material and/or material properties, such as the elastic deformability, the plastic deformability and/or in particular the modulus of elasticity. The method for calibrating and/or operating, in particular the test procedure, can be carried out when, in particular, the user starts the method, in particular by actuating the actuating element, when a blank, in particular for producing the object to be twisted, is replaced, when, in particular, the hand-held power tool is preferably transferred from the preparation mode into the operating state and/or when, in particular, a malfunction occurs, such as, in particular, when the object to be twisted is damaged in the normal operating state.

A "test step" is to be understood to mean, in particular, a method step which is different from normal operation and is provided, in particular, for the testing of a test object. In particular, the test object is manufactured before the test step is carried out. A "corresponding test object" is to be understood to mean, in particular, a test object which has object parameters at least substantially identical to the object to be twisted and which is preferably at least substantially identically constructed to the object to be twisted. "at least substantially identical" is to be understood in this context to mean, in particular, identical apart from manufacturing and/or material tolerances.

In this context, "twisting the object to be twisted" is to be understood in particular to mean that the object to be twisted is twisted, wound and/or twisted at least partially around itself or with itself and/or preferably around a further object, in particular a reinforcement. By "damaged object" is to be understood in particular that the object is at least plastically deformed and advantageously at least partially, in particular at least largely and particularly preferably completely, destroyed and/or torn open. The twisting is performed in particular as a function of at least one characteristic value. The characteristic value is in particular a value which is associated with a torque which acts on the object to be twisted during the twisting and which is in particular generated by the drive unit. In particular, the torque can be derived from the characteristic value and/or determined using the characteristic value. It is conceivable that this characteristic value corresponds to the torque. Advantageously, however, the characteristic value corresponds to a characteristic value that reflects the torque. In particular, the characteristic value corresponds to a particularly direct control and/or regulating variable of the drive unit. Advantageously, the characteristic value is in particular a signal that can be measured by a sensor unit of the hand-held power tool. Advantageously, the characteristic value is the current, the voltage and/or the rotational speed of the drive unit. In normal operation of the hand-held power tool, the characteristic value is increased until the characteristic value reaches and/or exceeds a reference operating characteristic value.

The object to be twisted can be, in particular, a tool element, such as a drill, a grinding plate, a saw blade, a tool bit and/or a tool bit. Preferably, the object to be twisted is a connection object provided for connecting at least two members, such as a screw. In a particularly preferred embodiment of the invention, it is provided that the object to be twisted is a wire for connecting a reinforcement. The reinforcement elements can thereby be connected to one another in a simple manner by means of wires.

It is further proposed that the method comprises at least one determining step in which at least one destruction characteristic value is determined, in which case the test object is destroyed by twisting. In the calibration operation, the characteristic value is increased in particular until a fault characteristic value is reached and/or exceeded. In particular, it is advantageously possible to estimate in a simple manner the forces acting on the object to be twisted, in particular the torque acting on the object, in the event of damage.

In a preferred embodiment of the invention, it is provided that the torque characteristic curve is sensed for determining the destruction characteristic value. In this context, a "torque characteristic curve" is to be understood to mean, in particular, at least one value curve and/or value table, which is provided for assigning at least two variables to one another. The torque characteristic curve can be stored in the memory unit as a table of values and/or as a mathematical function, in particular. Preferably, the torque characteristic is a trend of the characteristic values over time and preferably a characteristic value is assigned to each time point. The trend of the characteristic values over time during operation of the hand-held power tool can thus be advantageously determined.

It is also proposed that at least one local maximum of the torque characteristic curve be used as a fault characteristic value. Furthermore, the torque characteristic curve has a further local maximum which is different from the local maximum corresponding to the destruction characteristic value. The further local maximum temporally precedes the local maximum corresponding to the destruction feature value. The local maxima are used, in particular, to determine destruction characteristic values. The destruction characteristic value is preferably situated in time after at least one local minimum of the torsion characteristic curve. The destruction feature value can thus be determined more accurately.

Furthermore, it is proposed that the test object is produced by cutting to length at least at one point in time, the torque characteristic curve having a local minimum after this point in time. Preferably, the sensing of the local maxima is started after the local minima. In particular, the torque characteristic curve has a further local maximum at the time of the severing at a fixed length. The object is preferably produced from a blank by a hand-held power tool in at least one production step. In particular, a coil from which a wire is produced by cutting off, in particular to length, a length is provided as a blank for the object. The hand-held power tool comprises, in particular, at least one supply unit, which supplies blanks in at least one supply step, at least in part, for producing the object. This advantageously simplifies the determination of the destruction characteristic values.

In order to avoid damage to the object to be twisted in the normal operating state, it is proposed: the method comprises at least one calibration step, in which a torsional operating characteristic value is generated as a function of the destruction characteristic value, which is provided for twisting the object in a normal operating state of the hand-held power tool. The torque operating characteristic is a reference operating characteristic, in particular in the normal operating state. In particular, when and/or after the characteristic value for the torsional operation is reached in the normal operating state, the characteristic value of the drive unit is no longer increased further and the torsion is preferably terminated. In particular, the torque operating characteristic is smaller, in particular numerically smaller, than the failure characteristic. In particular, the destruction characteristic values are preferably weighted by means of a function in order to generate the torsional operating characteristic values. The function may in particular be a polynomial function of order n, where n represents any natural number. Preferably, the function is a constant coefficient, in particular smaller than 1, which preferably corresponds to a polynomial function of the zeroth order. In particular, the destruction characteristic is multiplied by the function in order to weight and generate the torque operation characteristic. In this way, the destruction characteristic values can be taken into account during normal operation in order to avoid damage to the object to be twisted.

In order to avoid an in particular incorrect calibration, it is proposed that, for the case in which the torque operating characteristic value is smaller than a nominal characteristic value, in particular stored in a memory unit, for twisting the object in the normal operating state of the hand-held power tool, an alternative torque operating characteristic value is generated, which is at least greater than the nominal characteristic value. In addition or alternatively, it is provided that the test step and preferably the method for calibration are at least partially repeated for the case of a torque operating characteristic value that is smaller than a stored nominal characteristic value.

It is proposed that the destruction characteristic value is the current and/or the rotational speed of the drive unit of the hand-held power tool. In this way, the disruptive characteristic value can be assigned to the control and/or regulating variable in a simple manner.

Furthermore, it is proposed that at least one torsional operating characteristic value generated in the calibration step, which is provided for twisting the object in a normal operating state of the hand-held power tool, is monitored in the normal operating state, in particular continuously, and is changed in the normal operating state as a function of whether a limit value is undershot or exceeded. It is advantageously possible to react to changing conditions during normal operating conditions in order to ensure an advantageously reliable winding of the reinforcement by means of the object configured as a wire.

Furthermore, it is proposed that at least one load characteristic value is used for generating and/or changing a torque operating characteristic value which is provided for twisting the object in a normal operating state of the hand-held power tool. The load characteristic value is preferably designed as a voltage characteristic variable and/or a current characteristic variable, which are associated with a characteristic variable, in particular a force and/or a torque, which suppresses twisting and/or twisting of the object. Preferably, at least one twist parameter is taken into account for generating and/or changing the torque operating characteristic value. The twist parameter is preferably the number (times) of twists and/or twists of the object, in particular around itself. Alternatively or additionally, it is conceivable to monitor the number of loops into which the object is wound, in order to obtain a quantifiable conclusion about, in particular, a failure of the object, in particular of the wire. With the configuration according to the invention, the load state of the object can advantageously be taken into account for generating and/or changing the torque operation characteristic value. During the generation and/or modification of the torsional operating characteristic values, the arrangement of the object to be twisted on the workpiece, in particular on the reinforcement, can advantageously be taken into account. Reliable limit values can advantageously be determined in order to ensure reliable winding of the reinforcement by means of the object designed as a wire.

In a further aspect of the invention, a hand-held power tool is proposed, which has at least one drive unit, which is provided for twisting at least one object, and at least one control unit, which is provided for actuating at least the drive unit in at least one operating state and which, in at least one calibration operating state, is provided for carrying out a method for calibration, in particular the method described above, wherein the control unit, in the calibration operating state, is provided for twisting a test object corresponding to the object at least to such an extent by means of the drive unit until the test object is damaged by the twisting. The efficiency, in particular the cost efficiency, of the hand-held power tool can thereby be advantageously improved. By "damaged object" is to be understood in particular that the object is at least plastically deformed and advantageously at least partially, in particular at least largely and particularly preferably completely, broken and/or split.

The hand-held power tool according to the invention and/or the method according to the invention should not be limited to the applications and embodiments described above. In particular, the hand-held power tool according to the invention and/or the method according to the invention may have a different number of method steps, elements, components and units than the number described here for implementing the operating modes described here.

Drawings

Further advantages result from the following description of the figures. Embodiments of the invention are illustrated in the drawings. The figures, description and claims contain a number of combination features. The person skilled in the art can also, in line with the objective, consider the features individually and summarize them into meaningful further combinations. Shown in the drawings are:

fig 1 shows a hand-held power tool with a drive unit and a control unit in a schematic side view,

fig. 2 shows a schematic flow diagram of the operation of a hand-held power tool, which flow diagram includes a method for calibration,

fig. 3 shows a schematic diagram of an exemplary torque characteristic curve.

Detailed Description

Fig. 1 shows a schematic representation of a hand-held power tool 10 in a side view. The hand-held power tool 10 is provided for twisting an object to be twisted. In the present case, the hand-held power tool 10 is designed as a reinforcement strapping machine. Alternatively or additionally, the hand-held power tool 10 may be designed as a drill, a hammer drill and/or a chisel, a saw, a plane, a screwdriver, a milling machine, a sander, an angle grinder, a garden appliance and/or a multi-function power tool.

The hand-held power tool 10 has at least one control unit 38. The control unit 38 comprises at least one control electronics. The control electronics have at least one processor unit. The processor unit is at least arranged for implementing an operating program. Furthermore, the control electronics have a memory unit. The running program is stored in the memory unit.

The hand-held power tool 10 has a drive unit 36. The control unit 38 is provided for actuating at least the drive unit 36 in at least one operating state. The drive unit 36 operates on the basis of at least one characteristic value. The drive unit 36 has a first drive direction. Furthermore, the drive unit 36 has a second drive direction. The second driving direction is different from the first driving direction. In the present case, the first drive direction corresponds to a clockwise drive. The second drive direction corresponds to a counterclockwise drive. The drive unit 36 is provided at least for driving at least one further unit of the hand-held power tool 10. The drive unit 36 operates on the basis of the characteristic values. The characteristic values are current, voltage and/or rotational speed.

The hand-held power tool 10 has a supply unit 42. The supply unit 42 is driven by the drive unit 36. The drive unit 36 is arranged for driving at least the supply unit 42 in a first drive direction. The supply unit 42 is provided for supplying blanks. The blank is arranged for manufacturing an object 12 to be twisted. The blank is a coil of wire. The hand-held power tool 10 produces an object 12 to be twisted from a blank.

The hand-held power tool 10 has a shaping unit 44. The supply unit 42 supplies the forming unit 44 at least partially with blanks. The forming unit 44 has a beak-like continuation. The forming unit 44 deforms the supplied portion of blank, i.e. the supplied portion of blank, in particular by means of said continuation. The forming unit 44 forms the supplied blank part into at least a ring. The forming unit 44 forms a different number of rings according to the requirements and in particular to the length of the supplied blank portion. The object to be twisted 12 is a wire for connecting a reinforcement.

The hand-held power tool 10 has a cutting unit 46. The cutting unit 46 is driven by the drive unit 36, in particular in a second drive direction. The cutting unit 46 is arranged for cutting off the supplied blank portion to length. The cutting unit 46 manufactures the object 12 to be twisted from the supplied blank portion. In particular, the cutting unit 46 cuts the supplied blank portion to length during twisting thereof.

The hand-held power tool 10 has a torque unit 40. The torsion unit 40 is driven by the drive unit 36, in particular in the second drive direction. By means of the twisting unit 40, the driving unit 36 twists the object 12 to be twisted.

Fig. 2 shows a schematic flow chart of the operation of hand-held power tool 10, which includes a method for calibrating and/or operating hand-held power tool 10.

The method includes a start-up step 50. Before the opening step 50, the control unit 38 is closed. In an activation step 50, the control unit 38 is activated.

The method includes an initialization step 52. In an initialization step 52, control unit 38 transitions into a preparation mode.

The method includes an activation step 54. In an activation step 54, control unit 38 switches from the standby mode into the operating state. In the present case, the control unit 38 is switched into the operating state by the user. The user switches the control unit 38 into the operating state by actuating an actuating element of the hand-held power tool 10. If the actuating element is not pressed, the hand-held power tool 10 remains in the ready mode.

The method comprises a first query step 56. In this first query step 56 it is queried whether a calibration should be performed. In order to operate the hand-held power tool 10, a reference operating characteristic value is predefined by the control unit 38, at which the drive unit 36 is operated. If calibration is not enabled, the reference operating characteristic is the torque operating characteristic 30. The reference operating characteristic value of the drive unit 36 can be increased to the torsional operating characteristic value 30 during operation without damaging the object 12 to be twisted. The torque operating characteristic 30 can be determined, for example, when a method for calibration and/or operation is carried out beforehand. The calibration should be carried out when the user starts the method, for example by manipulating the operating element. Alternatively or additionally, it is conceivable that the calibration is carried out when changing blanks provided for producing the object 12 to be twisted, when the control unit 36 is transferred, in particular, from the preparation mode into the operating state, and/or when a malfunction occurs, for example when the object 12 to be twisted is damaged, in particular in the normal operating state, a malfunction occurs.

The method has a setting step 58. The setup step 58 is performed when calibration is initiated. If calibration has not been initiated, the reference running characteristic is replaced by the maximum characteristic. The maximum characteristic value corresponds to a maximum characteristic value up to which the drive unit 36 can be operated.

The method includes a supplying step 60. In this supply step 60 a blank is supplied. For this purpose, the supply unit 42 is driven by the drive unit 36, in particular in a first drive direction. The supply unit 42 supplies the blank to the forming unit 44. The forming unit 44 deforms the supplied blank portion into at least one loop.

The method comprises a second query step 62. In a second query step 62, the number of rings of the blank is determined. If the number of rings is less than the required number, the supply step 60 continues. When the number of rings is greater than or equal to the required number, the supplying step 60 is ended.

The method includes a twisting step 64. When the supplying step 60 ends, a twisting step 64 is performed. In a twisting step 64, the supplied blank portion is twisted. For this purpose, the drive unit 36 drives the torsion unit 40, in particular in the second drive direction. The supplied blank portion is twisted by means of the drive unit 36.

The method includes a third query step 66. In this third query 66 it is queried whether the number of twists of the supplied blank part and/or the time set for the twist exceed a reference value. For the case of being below the reference value, the twisting step 64 is continued. If the reference value is exceeded, the twisting step 64 is ended.

The method comprises a testing step 14. When the twisting step 64 is finished, the test step 14 is performed. The testing step 14 comprises a first sub-step. In a first sub-step, the supplied blank portion continues to be twisted. Preferably, at least one load characteristic value is taken into account for generating and/or changing a torsional operating characteristic value 30, which is provided for twisting the object 12 in the normal operating state of the hand-held power tool 10. The drive unit 36 drives the cutting unit 46, in particular in the second drive direction. The cutting unit 46 cuts the supplied blank parts to length and produces the object 12 to be twisted and/or produces a test object corresponding to the object 12 to be twisted. In the present case, the object 12 to be twisted is a test object. In a further sub-step, the test object is twisted until it is damaged. For this purpose, the characteristic value of the operating drive unit 36 is increased until the test object is damaged and/or until a reference operating characteristic value is reached. In the present case, the characteristic value is the current at which the drive unit 36 operates. Alternatively or additionally, the characteristic value may be a rotational speed at which the drive unit 36 is operated.

The method comprises a fourth query step 68. In the fourth query step 68: whether the reference operating characteristic has been reached. If the reference operating characteristic has not been reached, test step 14 continues. If the reference operating characteristic value is reached, the test step 14 is ended. Alternatively or additionally, damage to the test object may be investigated. If the test object is damaged, the testing step may be ended. If the test object is not damaged, test step 14 continues.

The method includes a stopping step 70. When the test step 14 ends, a stop step 70 is performed. In a stop step 70, the drive unit 36 is stopped.

The method comprises a fourth query step 72. In this fourth query step 72, it is queried whether calibration has already been initiated. If calibration is not initiated, the activation step 54 is re-executed. If calibration has been initiated, the evaluation step 18 of the method is performed.

The method comprises an evaluation step 18. In this determination step 18, a destruction characteristic value 20 is determined. The destruction feature value 20 is a feature value when the test object is damaged by twisting. In order to determine the destruction characteristic 20, a torque characteristic 22 is sensed in a preceding method step, in particular in test step 14. An exemplary torque characteristic 22 is shown in fig. 3 in graph 82. The graph 82 has an abscissa axis 78. Time is plotted on the abscissa axis 78 in seconds. The graph 82 has an ordinate axis 80. On the ordinate axis 80, the feature value is plotted. In the present case, the characteristic value is the current for operating the drive unit 36. Alternatively or additionally, the characteristic value may be the rotational speed of the drive unit 36. The torque characteristic 22 has a local maximum 24. The failure characteristic 20 is a local maximum 24 of the torsion characteristic 22. The torque characteristic 22 has a local minimum 26. The destruction characteristic 20 is located temporally after the local minimum 26. The torque characteristic curve 22 has a local minimum 26 in time after the point in time at which the test object is produced by means of the cut-to-length cut. Furthermore, the torque characteristic curve 22 has a further local maximum 27. The second local maximum is temporally located before the local minimum 26. The damage characteristic 20 is determined by sensing the characteristic after passing the local minimum 26 until a local maximum is reached. Alternatively or additionally, the breach characteristic 20 may be sensed by a combination of a plurality of torsion characteristics. For example, the first torque characteristic curve may reflect a current trend of the drive unit 36 over time. The second torque characteristic curve may reflect the trend of the rotational speed of the drive unit 36 over time. The second torque profile has a local minimum. The local minimum is temporally preceding the point in time at which the first torque characteristic curve has the local maximum.

The method comprises a calibration step 28. A torque operation characteristic 30 is generated in the calibration step 28. The torque operating characteristic value 30 is provided for twisting the object 12 to be twisted in the normal operating state of the hand-held power tool 10. A torque operation characteristic value 30 is generated based on the failure characteristic value 20. In order to generate the torsional operating characteristic 30, the destruction characteristic 20 is weighted by means of a function. Which in the present case is a coefficient. The coefficient is less than 1. The damage characteristic 20 is multiplied by the function to produce a torque operation characteristic 30.

The method comprises a fifth query step 74. Nominal characteristic values are stored in the memory unit. In the case of a resulting torsional operating characteristic 30 which is greater than the nominal characteristic, the control unit 38 transitions into a preparation mode, in particular into an initialization step 52.

The method includes an overwrite (overwrite) step 76. If the generated torsional operating characteristic 30 is less than the nominal characteristic, an alternate torsional operating characteristic is generated. The alternative torsional operating characteristic is at least greater than the nominal characteristic. Alternatively or additionally, if the determined characteristic value 30 of the torsional operation is smaller than the stored nominal characteristic value, the test step 14 is repeated at least.

In a possible course of the method, the control unit 38 is switched on in a switching-on step 50. In an initialization step 52, control unit 38 transitions into a preparation mode. By actuating the actuating element by the user, the control unit 38 is switched from the standby mode into the operating state in an activation step 54. And (4) checking: the hand-held power tool 10 is loaded or unloaded in the calibration operating state. If the hand-held power tool 10 is in the calibration operating state, at least the torque operating characteristic 30 is determined by means of the test step 14 and/or by means of an alternative method process. During the test step 14 and/or the alternative method, the object 12, in particular configured as a wire, is supplied to the forming unit 44 in a supply step 60 by means of the supply unit 42. The number of wound loops of the object 12 is preferably monitored, in particular during the supply of the object 12 to the forming unit 44. If the number of wound rings of the object 12 is smaller than the predefined number, the supply of the object 12 to the forming unit 44 is continued in order to wind more rings of the object 12. If the number of wound loops of the object 12 is greater than or equal to a predetermined number, the supply is stopped and the object 12 is twisted by means of the twisting unit 40. During the twisting of the object 12 by means of the twisting unit 40, the rotational speed and/or the current of the drive unit 36 is preferably monitored. Upon identification of a repeated speed disturbance of the drive unit 36, for example five consecutive speed disturbances or the like, the maximum current characteristic value of the drive unit 36 sensed during the speed disturbance and the amount of twisting of the object 12 sensed up to the speed disturbance are stored in the memory unit. It is contemplated that the testing step 14 may be eliminated or alternatively the testing step 14 may be performed after identifying repeated speed disturbances. The maximum current characteristic value stored in the memory unit is stored in the memory unit as an upper limit value of the current of the drive unit 36, wherein this limit value can be taken into account as a reference for identifying and/or for avoiding damage to the object 12 during normal operating conditions. In particular, the upper limit value of the current of the drive unit 36 constitutes the destruction characteristic value 20. The number of twists stored in the memory unit is stored in the memory unit as an upper limit value for the number of twists, wherein this limit value can be taken into account as a reference for identifying and/or for avoiding damage to the object 12 during normal operating conditions. Preferably, the upper limit value of the current of the drive unit 36 and the upper limit value of the number of torsions during the torsion of the object 12 for connecting workpieces, in particular stiffeners, are monitored.

In the calibration operating state, at least one load characteristic value of the hand-held power tool 10 is sensed, which enables: whether the hand-held power tool 10 is arranged on a workpiece, in particular a reinforcement. It can advantageously be sensed that: the hand-held power tool 10 is operated under load or under no load. For example, it is conceivable for the hand-held power tool 10 to have a distance sensor, a contact sensor or other sensors that appear to be useful to a person skilled in the art, by means of which it can be sensed whether the hand-held power tool 10 is arranged on a workpiece. When it is detected that the hand-held power tool 10 is arranged on a workpiece, in particular a reinforcement, and a rotation of the object 12 is carried out on the workpiece, the upper limit value stored in the memory unit is preferably compared with the newly sensed value. If the deviation of the newly sensed value from the upper limit value stored in the memory unit exceeds the permissible range, a renewed determination of the upper limit value is preferably carried out in the memory unit, in particular in a manner similar to the method procedure already described above, for example by monitoring the rotational speed and/or the current of the drive unit 36 and subsequently evaluating and storing it in the memory unit. It is conceivable to change only one of the upper limit values or to change both upper limit values.

In a normal operating state with or without load, it is preferably monitored in the normal operating state and, depending on whether the upper limit value stored in particular in the memory unit is undershot or exceeded, at least one torsional operating characteristic value 30 generated in the calibration step 28 is changed in the normal operating state, which is provided for twisting the object 12 in the normal operating state of the hand-held power tool 10. In the normal operating state, at least one load characteristic value of the hand-held power tool 10 is sensed, which enables: whether the hand-held power tool 10 is arranged on a workpiece, in particular a reinforcement. It is advantageously possible to sense: the hand-held power tool 10 is operated under load or under no load. Preferably, the control unit 38 automatically switches the operating state between: i.e. between a normal operating state and a calibration operating state.

In the normal operating state, the comparison of the upper limit value stored in the memory unit with the newly sensed value is preferably carried out when it is recognized that the hand-held power tool 10 is arranged on a workpiece, in particular a reinforcement, and a twisting of the object 12 is carried out on the workpiece. If the deviation of the newly sensed value from the upper limit value stored in the memory unit exceeds the permissible range, a renewed determination of the upper limit value is preferably carried out in the memory unit, in particular in a manner similar to the method procedure already described above, for example by monitoring the rotational speed and/or the current of the drive unit 36 and subsequently evaluating and storing it in the memory unit. It is conceivable to change only one of the upper limit values or to change both upper limit values.

If damage to the object 12 is detected, in particular if the object 12 breaks due to twisting, an alternative torsional operating characteristic value can preferably be generated in the normal operating state. The alternative characteristic value for torsional operation is preferably smaller than the characteristic value for torsional operation 30, in particular in order to enable a reduction of the upper limit value stored in the memory unit, which can avoid damage to the object 12 due to twisting of the object 12. Preferably, the alternative torsional operating characteristic can be generated by: the damage characteristic 20 generated in the determination step 18 can be multiplied by an alternative factor that is less than 1 and greater than the factor by which the damage characteristic 20 can be multiplied to generate the torsional operating characteristic 30.

If it is detected that the object 12 is loosely lying around the workpiece, in particular because the object 12 is twisted too few times or with too low a power of the drive unit 36, it is preferably possible to generate additional torque operating characteristic values in the normal operating state. The additional characteristic value for the torsional operation is preferably greater than the characteristic value for the torsional operation 30, in order to be able to increase, in particular, the upper limit value stored in the memory unit, which enables the object 12 to be reliably and firmly attached to the workpiece as a result of the twisting of the object 12. Preferably, the additional torque operating characteristic value can be generated by: the destructive characteristic values 20 generated in the solving step 18 can be multiplied by an additional coefficient greater than 1. Advantageously, the characteristic values for operating the hand-held power tool 10 can be individually changed during continuous operation.

Claims

1. A method for calibrating and/or operating a hand-held power tool (10) which is provided for twisting at least one object (12) to be twisted, characterized in that at least one test step (14) is provided, in which a test object corresponding to the object (12) to be twisted is twisted at least to such an extent that the test object is damaged by the twisting, at least one determination step (18) is provided, in the determination step, at least one characteristic value of damage (20) is determined, in the case of which the test object is damaged by twisting, at least one calibration step (28) is provided, in the calibration step, a torque operation characteristic value (30) is generated according to the damage characteristic value (20), the torque operating characteristic value is provided for twisting the object (12) in a normal operating state of the hand-held power tool (10).

2. Method according to claim 1, characterized in that the object (12) to be twisted is a wire for connecting reinforcement.

3. Method according to claim 1 or 2, characterized in that a torque characteristic curve (22) is sensed for determining the destruction characteristic value (20).

4. Method according to claim 3, characterized in that at least one local maximum (24) of the torsion characteristic curve (22) is used as a destruction characteristic value (20).

5. Method according to claim 3, characterized in that values lying temporally after at least one local minimum (26) of the torsion characteristic curve (22) are used as destruction characteristic values (20).

6. Method according to claim 5, characterized in that the test object is produced by cut-to-length at least one point in time, wherein the torque characteristic curve (22) has the local minimum (26) after this point in time.

7. Method according to claim 1, characterized in that for generating the torsional operating characteristic (30), the destruction characteristic (20) is weighted by means of a function.

8. Method according to claim 1, characterized in that for the case in which the torsional operating characteristic (30) is smaller than the stored nominal characteristic, a substitute torsional operating characteristic is generated for twisting the object (12) in the normal operating state of the hand-held power tool (10), which substitute torsional operating characteristic is at least greater than the nominal characteristic.

9. Method according to claim 1, characterized in that the test step (14) is repeated at least for the case where the torque running characteristic (30) is smaller than the stored nominal characteristic.

10. Method according to claim 2, characterized in that the destruction characteristic value (20) is the current and/or the rotational speed of a drive unit (36) of the hand-held power tool (10).

11. The method according to claim 1 or 2, characterized in that at least one torsional operating characteristic (30) generated in the calibration step (28) is monitored in a normal operating state and is changed in the normal operating state as a function of whether a limit value is undershot or exceeded, which torsional operating characteristic is provided for twisting the object (12) in the normal operating state of the hand-held power tool (10).

12. Method according to claim 1 or 2, characterized in that at least one load characteristic value is taken into account for generating and/or changing a torsional operating characteristic value (30) which is provided for twisting the object (12) in a normal operating state of the hand-held power tool (10).

13. The method according to claim 1 or 2, characterized in that the hand-held power tool is a reinforcement strapping machine.

14. A hand-held power tool (10) having at least one drive unit (36) which is provided for twisting at least one object (12) to be twisted and at least one control unit (38) which is provided for actuating at least the drive unit (36) in at least one operating state and which, in at least one calibration operating state, is provided for carrying out the method according to one of the preceding claims, characterized in that the control unit (38), in the calibration operating state, is provided for twisting a test object corresponding to the object (12) by means of the drive unit (36) at least to such an extent that the test object is damaged by the twisting.

15. The hand-held power tool (10) according to claim 14, characterized in that the hand-held power tool (10) is a reinforcement strapping machine.