EP4368346A1 - Procédé d'opération d'une machine-outil portative - Google Patents

Procédé d'opération d'une machine-outil portative Download PDF

Info

Publication number: EP4368346A1
Authority: EP; European Patent Office
Prior art keywords: signal; operating; application class; operating variable; power tool
Prior art date: 2022-11-08
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.): Pending

Application number

EP23203789.5A

Other languages

German (de)

English (en)

Inventor

Tobias Herr

Wolfgang Herberger

Marcus Schuller

Simon Erbele

Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Robert Bosch GmbH

Original Assignee

Robert Bosch GmbH

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

2022-11-08

Filing date

2023-10-16

Publication date

2024-05-15

2023-10-16 Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH

2024-05-15 Publication of EP4368346A1 publication Critical patent/EP4368346A1/fr

Status Pending legal-status Critical Current

Images

Classifications

- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
- B25B23/00—Details of, or accessories for, spanners, wrenches, screwdrivers
- B25B23/14—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers
- B25B23/147—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers specially adapted for electrically operated wrenches or screwdrivers
- B25B23/1475—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers specially adapted for electrically operated wrenches or screwdrivers for impact wrenches or screwdrivers
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
- B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
- B25B21/02—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose with means for imparting impact to screwdriver blade or nut socket

Definitions

the invention relates to a method for operating a hand-held power tool and to a hand-held power tool designed to carry out the method.
the present invention relates to a method for screwing in or unscrewing a threaded means with a hand-held power tool, preferably with an impact wrench.
a rotary impact wrench of this type comprises, for example, a structure in which an impact force in a direction of rotation is transmitted to a screw element by a rotary impact force of a hammer.
the rotary impact wrench having this structure comprises a motor, a hammer driven by the motor, an anvil which is struck by the hammer, and a tool.
the motor built into a housing is electrically driven, the hammer is driven by the motor, the anvil is in turn struck by the rotating hammer and an impact force is transmitted to the tool, whereby two different operating states, namely "no impact operation” and "impact operation”, can be distinguished.
From the EN 20 2017 0035 90 is also known as an electrically powered tool with an impact mechanism, where the hammer is driven by the motor.
the aim is to achieve an ever greater output torque in the area of devices that are traditionally operated with a hexagon bit in order to achieve rapid work progress with maximum torque in the most commonly used work case, the so-called "soft" screw case in wood and particularly softwood.
the soft screw base offers little resistance to the high torques and the reaction forces acting on the device and the bit are correspondingly low and do not pose a problem with regard to the strength of the materials used in the bit and hand tool.
the object of the invention is to provide a method for operating a hand-held power tool which is improved compared to the prior art and which at least partially eliminates the above-mentioned disadvantages, or at least to provide an alternative to the prior art.
a further object is to provide a corresponding hand-held power tool.
a further object of the invention is to provide the user with a hand-held power tool that allows him to have the full speed, the full torque, and thus the full power available in soft screwdriving applications, while he can work with the same device in hard screwdriving applications at reduced speed and reduced torque in order to avoid the bits breaking off.
a method for operating a hand-held power tool comprising the steps: S1 Selecting an application class depending on at least one hardness and/or strength property of a substrate in which a screw connection is to be made; S2 selecting an operating mode from an operating mode group comprising a first operating mode and a second operating mode based at least in part on the application class; wherein the first operating mode has a first maximum torque level delivered by the hand-held power tool per application class and the second operating mode has a second maximum torque level per application class.
the method according to the invention effectively supports a user of the hand-held power tool in achieving reproducible, high-quality application results, while ensuring that work is always carried out with a torque level appropriate to the respective application class. In particular, it can be prevented that damage to a tool bit occurs due to excessive torque.
an application class is to be understood in the broadest sense as the use of the hand-held power tool for a specific purpose.
the application class can be determined, for example, by a property of the material that forms the substrate in which the screw connection is to take place, or in other words, the screw base.
the application classes "hard screw case” and “soft screw case” can be defined, depending on whether the screw base is categorized as “hard” or "soft”.
a “hard” screw base would be hardwood, metal or concrete, for example, while a “soft” screw base would be softwood or certain plastics, for example.
the determining material property for distinguishing between the application classes “hard” and “soft” screw cases would therefore be the surface hardness of the screw base.
an operating mode is understood to mean a presetting of one or more parameters which determine or influence the operation of the hand-held power tool, and in particular the level of torque which the hand-held power tool delivers.
Such parameters can be, for example, a maximum speed of the electric motor and/or a maximum impact duration during which the anvil delivers impacts on a screw head.
the respective first maximum torque level is higher than the corresponding second maximum torque level for each application class.
the second operating mode is also referred to as "protective mode" because the lower torque level compared to the first operating mode enables a reduced stress on the components involved in the screwing process on the machine, tool and fastener side.
the respective second maximum torque level may be characterized by a lower speed of the electric motor and/or a shorter impact duration compared to the corresponding first torque level.
the first operating mode can be selected if the application class is soft screw joint and the second operating mode can be selected if the application class is hard screw joint.
the application class can be selected by a user, optionally via application software ("app") installed on an external device, for example a smartphone, a tablet, or a computer, and/or a user interface on the handheld power tool (100) ("Human-Machine Interface", "HMi").
apps application software
an external device for example a smartphone, a tablet, or a computer
HMi Human-Machine Interface
the operating mode in step S2 can be selected by a user, optionally via an application software ("app") and/or a user interface on the handheld power tool (100) ("human-machine interface", "HMI").
apps application software
HMI human-machine interface
the operating mode can be selected at least partially automatically in step S2.
"Partially automatically” means that a user is suggested an operating mode based on a machine evaluation, which will be explained in more detail below, which the user can then confirm or reject. In the case of an automatic selection, the user is not asked for such confirmation when determining the operating mode.
step S1 the selection of the application class can be carried out at least partially automatically.
a partially automatic selection means that the user can accept or reject a machine-side suggestion.
the user will not be asked for such confirmation when defining the application class.
model signal forms of different application classes are predefined in method step S1.2, in particular specified at the factory.
the model signal forms are stored or saved internally in the device, alternatively and/or additionally provided to the hand-held power tool, and in particular provided by an external data device.
the model signal shape is an oscillation curve, such as an oscillation curve around a mean value, in particular an essentially trigonometric oscillation curve.
the signal of the operating variable can be compared with the model signal shapes by means of a comparison method to determine whether at least a predetermined threshold value of agreement is met.
the comparison method comprises at least one frequency-based comparison method and/or one comparative comparison method.
the decision can be made at least partially by means of the frequency-based comparison method, in particular a bandpass filtering and/or a frequency analysis, as to whether a certain application class, hereinafter also referred to as the "application class to be recognized", has been identified in the signal of the operating variable.
the frequency-based comparison method in particular a bandpass filtering and/or a frequency analysis, as to whether a certain application class, hereinafter also referred to as the "application class to be recognized", has been identified in the signal of the operating variable.
the frequency-based comparison method comprises at least bandpass filtering and/or frequency analysis, wherein the predetermined threshold value is at least 90%, in particular 95%, most particularly 98%, of a predetermined limit value.
bandpass filtering for example, the recorded signal of the operating variable is filtered via a bandpass whose passband matches the model signal shape. A corresponding amplitude in the resulting signal is to be expected if the relevant application class to be recognized is present.
the specified threshold value of the bandpass filtering can therefore be at least 90%, in particular 95%, and most particularly 98%, of the corresponding amplitude in the application class to be recognized.
the specified limit value can be the corresponding amplitude in the resulting signal of an ideal application class to be recognized.
the previously defined model signal shape for example a
the frequency spectrum of the application class to be identified is searched for in the recorded signals of the operating variable.
a corresponding amplitude of the application class to be identified is to be expected.
the specified threshold value of the frequency analysis can be at least 90%, in particular 95%, and most particularly 98%, of the corresponding amplitude of the application class to be identified.
the specified limit value can be the corresponding amplitude in the recorded signals of an application class to be identified. In this case, an appropriate segmentation of the recorded signal of the operating variable may be necessary.
the comparative comparison method comprises at least one parameter estimation and/or a cross-correlation, wherein the predetermined threshold value is at least 40% of a match between the signal of the operating variable and the model signal shape.
the measured signal of the operating variable can be compared with the model signal shape using the comparative comparison method.
the measured signal of the operating variable is determined in such a way that it has essentially the same finite signal length as that of the model signal shape.
the comparison of the model signal shape with the measured signal of the operating variable can be output as a signal of a finite length, in particular a discrete or continuous one. Depending on the degree of agreement or deviation of the comparison, a result can be output as to whether the application class to be recognized is present. If the measured signal of the operating variable matches the model signal shape by at least 40%, the application class to be recognized can be present.
the comparative method can output a degree of comparison to one another as a result of the comparison by comparing the measured signal of the operating variable with the model signal shape.
the comparison of at least 60% to one another can be a criterion for the presence of an application class to be recognized. It can be assumed that the lower limit for agreement is 40% and the upper limit for agreement is 90%.
a comparison can be made in a simple manner between the previously defined model signal shape and the signal of the operating variable.
estimated parameters of the model signal shape can be identified in order to adjust the model signal shape to the measured signal of the operating variables.
a result can be determined as to whether the application class to be recognized is present.
the result of the comparison can then be further evaluated to determine whether the specified threshold value has been reached. This evaluation can either be a quality determination of the estimated parameters or the agreement between the defined model signal shape and the recorded signal of the operating variable.
method step S1.3 contains a step S1.3a of determining the quality of the identification of the model signal shape in the signal of the operating variable, wherein in method step S1.4 the recognition of the application class is carried out at least partially on the basis of the quality determination. As a measure of the quality determination, a quality of fit of the estimated parameters can be determined.
a decision can be made, at least in part, by means of the quality determination, in particular the measure of quality, as to whether the application class to be recognized has been identified in the signal of the operating variable.
method step S1.3a can include a comparison determination of the identification of the model signal shape and the signal of the operating variable.
the comparison of the estimated parameters of the model signal shape to the measured signal of the operating variable can be, for example, 70%, in particular 60%, most particularly 50%.
the decision as to whether the application class to be recognized is present is made, at least in part, based on the comparison determination.
the decision as to whether the application class to be recognized is present can be made at the predetermined threshold value of at least 40% agreement between the measured signal of the operating variable and the model signal shape.
a comparison can be made between the previously defined model signal shape and the measured signal of the operating variable.
the previously defined model signal shape can be correlated with the measured signal of the operating variable.
a degree of agreement between the two signals can be determined.
the degree of agreement can be, for example, 40%, in particular 50%, and most particularly 60%.
the application class can be identified at least partially based on the cross-correlation of the model signal shape with the measured signal of the operating variable.
the identification can be carried out at least partially based on the predetermined threshold value of at least 40% agreement between the measured signal of the operating variable and the model signal shape.
the threshold value of the match can be set by a user of the hand-held power tool and/or is predefined at the factory.
additional sensor units for recording the tool-internal measurement variables such as an acceleration sensor unit, are essentially dispensed with.
the method step SM can thus further comprise storing and classifying signals of the operating variable assigned to the example applications in at least one or more application classes, and generating model signal forms assigned to the application classes from the signals of the operating variable.
the example applications can be executed by the user of the hand tool and/or read from a database.
the operating variable can be the speed of the electric motor or an operating variable that correlates with the speed.
the rigid gear ratio of the electric motor to the impact mechanism results in a direct dependency between the motor speed and the impact frequency.
Another conceivable operating variable that correlates with the speed is the motor current.
a motor voltage, a Hall signal from the motor, a battery current or a battery voltage are also conceivable as an operating variable of the electric motor, whereby an acceleration of the electric motor, an acceleration of a tool holder or a sound signal from an impact mechanism of the hand-held power tool are also conceivable as an operating variable.
the signal of the operating variable can be recorded in process step S1.1 as a time course of measured values of the operating variable, or as measured values of the Operating variable as a variable of the electric motor that correlates with the course of time.
Quantities of the electric motor that correlate with the course of time can be, for example, an acceleration, a jerk, in particular of a higher order, a power, an energy, an angle of rotation of the electric motor, an angle of rotation of the tool holder, or a frequency.
step S1.1a If the signal of the operating variable is recorded in process step S1.1 as a time profile of measured values of the operating variable, in a step S1.1a following process step S1.1, the time profile of the measured values of the operating variable is transformed into a profile of the measured values of the operating variable as a variable of the electric motor that correlates with the time profile on the basis of a rigid gear ratio of the transmission. This again results in the same advantages as with the direct recording of the signal of the operating variable over time.
the signal of the operating variable should be understood here as a temporal sequence of measured values.
the signal of the operating variable can also be a frequency spectrum.
the signal of the operating variable can also be reworked, for example smoothed, filtered, fitted and the like.
the signal of the operating variable is stored as a sequence of measured values in a memory, preferably a ring buffer, in particular of the hand-held power tool.
a further subject of the invention is a hand-held power tool comprising an electric motor, a measuring sensor of an operating variable of the electric motor, and a control unit, wherein the hand-held power tool advantageously comprises an impact wrench, in particular a Rotary impact wrench, and the hand-held power tool is set up to carry out the method described above.
the electric motor of the hand-held power tool causes an input spindle to rotate, and an output spindle is connected to the tool holder.
An anvil is connected to the output spindle in a rotationally fixed manner, and a hammer is connected to the input spindle in such a way that, as a result of the rotation of the input spindle, it executes an intermittent movement in the axial direction of the input spindle and an intermittent rotary movement around the input spindle, whereby the hammer intermittently strikes the anvil and thus delivers an impact and a rotational impulse to the anvil and thus to the output spindle.
a first sensor transmits a first signal to the control unit, for example to determine a motor rotation angle.
a second sensor can transmit a second signal to the control unit to determine a motor speed.
the hand-held power tool has a memory unit in which various values can be stored.
the hand-held power tool is a battery-operated hand-held power tool, in particular a battery-operated impact wrench. This ensures flexible and mains-independent use of the hand-held power tool.
the hand-held power tool is an impact wrench, in particular a rotary impact wrench.
the identification of the impacts of the impact mechanism of the hand-held power tool, in particular the impact oscillation periods of the electric motor, can be achieved, for example, by using a Fas-Fitting algorithm, by means of which an evaluation of the impact detection can be enabled within less than 100 ms, in particular less than 60 ms, most particularly less than 40 ms.
the present invention makes it possible to largely dispense with more complex methods of signal processing such as filters, signal loops, system models (static and adaptive) and signal tracking.
these methods allow an even faster identification of the impact mode or application class, which can cause an even faster response from the tool. This applies in particular to the number of impacts that have passed since the impact mechanism was activated until identification and also in special operating situations such as the start-up phase of the drive motor. Furthermore, the functioning of the algorithm is also independent of other influencing factors such as the target speed and battery charge level.
the hand-held power tool is a cordless screwdriver, a drill, an impact drill or a hammer drill, whereby a drill, a core bit or various bit attachments can be used as a tool.
the hand-held power tool according to the invention is designed in particular as an impact wrench, whereby the pulsed release of the motor energy generates a higher peak torque for screwing in or unscrewing a screw or a nut.
the transmission of electrical energy is to be understood in particular as meaning that the hand-held power tool transmits energy to the body via a battery and/or via a power cable connection.
the screwing tool can be designed to be flexible in the direction of rotation. In this way, the proposed method can be used both for screwing in and for unscrewing a screw or a nut.
decide should also be understood as recognizing or detecting, whereby a clear assignment should be achieved.
Identify should be understood as recognizing a partial match with a pattern, which can be made possible, for example, by fitting a signal to the pattern, a Fourier analysis or the like.
the "partial match” should be understood in such a way that the fitting has an error that is less than a predetermined threshold, in particular less than 30%, most particularly less than 20%.
the Figure 1 shows a hand-held power tool 100 according to the invention, which has a housing 105 with a handle 115.
the hand-held power tool 100 can be mechanically and electrically connected to a battery pack 190 for mains-independent power supply.
the hand-held power tool 100 is designed, for example, as a cordless impact wrench.
the present invention is not limited to cordless impact wrenches, but can in principle be used in hand-held power tools 100 in which the detection of work progress is necessary, such as impact drills.
An electric motor 180 which is supplied with power by the battery pack 190, and a gear 170 are arranged in the housing 105.
the electric motor 180 is connected to an input spindle via the gear 170.
a control unit 370 is arranged within the housing 105 in the area of the battery pack 190, which acts on the electric motor 180 and the gear 170 for controlling and/or regulating them, for example by means of a set motor speed n, a selected angular momentum, a desired gear x or the like.
the electric motor 180 can be operated, ie switched on and off, for example, via a manual switch 195, and can be any type of motor, for example an electronically commutated motor or a direct current motor.
the electric motor 180 can be electronically controlled or regulated in such a way that both reversing operation and specifications regarding the desired Motor speed n and the desired angular momentum can be realized.
the functionality and structure of a suitable electric motor are sufficiently known from the state of the art, so that a detailed description is omitted here for the sake of brevity.
a tool holder 140 is rotatably mounted in the housing 105 via an input spindle and an output spindle.
the tool holder 140 serves to hold a tool and can be molded directly onto the output spindle or connected to it in the form of an attachment.
the control unit 370 is connected to a power source and is designed such that it can control or regulate the electric motor 180 electronically using various current signals.
the various current signals provide different rotational impulses for the electric motor 180, with the current signals being passed to the electric motor 180 via a control line.
the power source can be designed, for example, as a battery or, as in the exemplary embodiment shown, as a battery pack 190 or as a mains connection.
control elements may be provided to set different operating modes and/or the direction of rotation of the electric motor 180.
a method for operating the handheld power tool 100 is provided, by means of which an overload of certain components or extensions of the handheld power tool 100, for example an overload of a tool bit received in the tool holder 140, can be prevented.
the basic idea is to carry out an application class in a step S1 depending on at least one hardness and/or strength property of a substrate or a screw base in which a screw connection is to take place, and to select an operating mode from an operating mode group comprising a first operating mode and a second operating mode, at least partially based on the application class, in a step S2.
the first operating mode has a first torque level delivered by the hand-held power tool 100 per application class and the second operating mode has a second maximum torque level per application class.
the operating mode which has a lower torque level for each application class than the other operating mode, is therefore also referred to below as "gentle mode".
the application class can be determined, for example, by a property of the material that forms the screw base, and in embodiments of the invention a "hard screw case” and “soft screw case” are defined depending on whether the screw base is "hard” or "soft”.
a "hard” screw substrate is considered to include, for example, hardwood, metal, or concrete, while examples of a “soft” screw substrate include softwood or certain plastics.
Figure 2 shows a flow chart of an embodiment of the method in which a user can configure the hand-held power tool 100 to run in gentle mode via software ("app") running on a terminal device such as a computer, a smartphone, or a tablet.
a terminal device such as a computer, a smartphone, or a tablet.
the control unit 370 of the handheld power tool 100 is connected to the app running on the corresponding terminal device, for example via a radio connection.
the app running on the corresponding terminal device, for example via a radio connection.
a corresponding user interface of the app it is possible to select an application class from a group of application classes and an operating mode from an operating mode group.
the user selects an application class at 202 in method step S1, such as the application class "soft screw joint” or the application class “hard screw joint”, the latter being represented in the app, for example, by the application "metal screw”.
step S2 the selection of the operating mode in step S2 is also carried out by the user via the app.
the second operating mode which, as already mentioned, is a gentle mode.
this causes the maximum torque level of the hand-held power tool 100 to be reduced compared to a maximum torque level that is possible when selecting the first operating mode, regardless of all other settings that the user may make.
the following additional process steps can be carried out:
the user can deactivate the gentle mode at 20610. In this case, the machine automatically switches back to the first operating mode.
the user can connect the handheld power tool at 20620 to another terminal device, for example to another smartphone.
a query is made via the app running on the new terminal device as to whether the settings stored in the handheld power tool 100 should be adopted or overwritten. If the user selects "Apply”, the settings stored in the control unit 370 at 20622 are adopted in the app, and if the user selects "Overwrite”, the settings stored in the control unit 370 of the handheld power tool 100 are overwritten by the app with preset settings.
the application class and operating mode selection made by the user remains active at 20631.
the hand tool 100 can be configured for the application or user-specific so that it can work with maximum power in soft screwing applications, while it can work with reduced power in hard screwing applications, but optimized for the strength of the tool used.
FIG 3 shows an embodiment in which the user can make certain additional settings in the app, which is explained in more detail below.
the selection of the application class in step S1 and the selection of the operating mode in step S2 are carried out by the user via the app.
the control unit 370 of the handheld power tool 100 is connected to the app running on the corresponding terminal device.
the user selects the application class, and at 204 he selects the second operating mode in the example, which in the example is the gentle mode.
the user takes, in contrast to the Figure 2 shown embodiment, further settings are provided, whereby these settings can be managed in a menu of the app, for example in different subgroups, for example in the groups “Basic”, “Performance”, and “Expert”, each of which can allow different configuration levels of the operation of the hand-held power tool 100, for example certain start-up characteristics of the electric motor 180, and also with regard to the pre-assignment of certain operating parameters such as the preset torque.
the maximum torque level of the handheld power tool 100 is then limited independently of all other settings, taking into account different accessories used together with the handheld power tool 100 and their load capacity when determining the torque level.
the settings made in step 305 are taken into account, for example different torque horizons between the "Basic”, “Performance” and “Expert” groups.
FIG. 4 shows an embodiment in which the user selects the application class in method step S1 and the operating mode in method step S2 by means of a human-machine interface (HMI), or alternatively by means of a push button, directly on the hand-held power tool.
HMI human-machine interface
the user can activate and change 400 preset speed levels and other operating parameters via the HMI, and also selects the application class via the HMI (in process step S1).
these presets can also be personalized and changed via an app.
the user in the example selects the second operating mode (for example the "gentle mode") (in method step S2), either via the HMI or, if the hand-held power tool has a push button provided for this purpose, via this push button.
the second operating mode for example the "gentle mode"
Figure 5 shows an embodiment in which the protection mode is activated for a period of time during which the user holds down a push button provided for this purpose at 504.
the selection of the application class in step S1 and the selection of the operating mode in step S2 are carried out by the user, namely via the HMI.
the user can activate and change preset speed levels and other operating parameters via the HMI, and also selects the application class via the HMI (in process step S1).
these presets can also be personalized and changed via an app.
the user presses the push button and thereby activates the gentle mode in process step S2.
the machine then automatically deactivates the protection mode.
FIG 6 shows an embodiment in which the selection of the application class in step S1 is carried out by the user, for example as in the Figures 2 to 5 described, while the selection of the operating mode in step S2 is done automatically.
the user can activate and change preset speed levels and other operating parameters via the app or via the HMI, and he also selects the application class via the app or via the HMI (in process step S1).
these presets can also be personalized and changed via an app.
control unit 370 automatically selects the application class (step S1), for example by executing internal device software. Further details on how the application case is automatically selected are given below.
control unit 370 for example also by executing the internal device software, automatically selects the operating mode (step S2), based at least in part on the selected application class.
step S1 If the application class "hard screwing case" is selected in step S1, the control unit 370 automatically selects the second operating mode in step S2, which, as described above, is a gentle mode with a reduced maximum torque level.
step S1 If the application class "soft screwing case" is selected in step S1, the control unit 370 automatically selects the first operating mode in step S2, which has a higher maximum torque level than the second operating mode.
step S1 The automatic selection of the application class in step S1 is described in more detail below.
aspects of the method are based, among other things, on an examination of signal shapes and a determination of the degree of agreement between these signal shapes and known signal shapes, such as those that occur in hard or soft screw joints.
FIG. 7 an exemplary signal of an operating variable 200 of an electric motor 180 of a rotary impact wrench is shown, as it occurs in this or a similar form during the intended use of a rotary impact wrench. While the following statements refer to a rotary impact wrench, they also apply analogously to other hand-held power tools 100, such as impact drills, within the scope of the invention.
the abscissa x represents the Figure 2 the time is plotted as a reference value.
a value correlated with time is plotted as a reference value, such as the angle of rotation of the tool holder 140, the angle of rotation of the electric motor 180, an acceleration, a jerk, in particular of a higher order, a power, or an energy.
the motor speed n present at any time is plotted on the ordinate f(x) in the figure.
f(x) represents, for example, a signal of the motor current.
Motor speed and motor current are operating variables that are usually recorded by a control unit 370 in hand-held power tools 100 without additional effort.
a Users of the handheld power tool 100 select based on which operating size the inventive method is to be carried out.
Fig. 7(a) shows an application of a loose fastening element, for example a screw 900, in a fastening support 902, for example a wooden board.
the signal comprises a first region 310, which is characterized by a monotonous increase in the engine speed, as well as a region of comparatively constant engine speed, which can also be referred to as a plateau.
the intersection point between abscissa x and ordinate f(x) in Figure 7(a) corresponds to the start of the impact wrench during the screwing process.
the screw 900 encounters a relatively low resistance in the fastening support 902, and the torque required for screwing in is below the disengagement torque of the rotary impact mechanism.
the course of the motor speed in the first area 310 therefore corresponds to the operating state of screwing without impact.
the screw 900 no longer rotates or only rotates by a significantly smaller angle of rotation.
the rotary impact operation carried out in the second 322 and third area 324 is characterized by an oscillating course of the signal of the operating variable 200, the form of the oscillation being, for example, trigonometric or can be oscillating in other ways.
the oscillation has a course that can be described as a modified trigonometric function.
This characteristic form of the signal of the operating quantity 200 in impact wrench operation is caused by the winding up and free running of the impact mechanism striker and the system chain located between the impact mechanism and the electric motor 180, including the gear 170.
the qualitative signal form of the impact operation is therefore known in principle due to the inherent properties of the rotary impact wrench.
at least one state-typical model signal form 240 is provided on the basis of this knowledge in a step S1.2, wherein the state-typical model signal form 240 is assigned to an application class, for example a soft or a hard screw case.
the state-typical model signal form 240 contains features typical for the application class such as the presence of a vibration curve, vibration frequencies or amplitudes, or individual signal sequences in continuous, quasi-continuous or discrete form.
the application class may be characterized by signal shapes other than oscillations, such as discontinuities or growth rates in the function f(x).
the state-typical model signal shape is characterized by these parameters instead of oscillations.
the state-typical model signal form 240 can be defined by a user in method step S1.1.
the state-typical model signal form 240 can also be stored or saved internally in the device.
the state-typical model signal form can alternatively and/or additionally be provided to the hand-held power tool 100, for example by an external data device.
a method step S1.3 of the method according to the invention the signal of the operating variable 200 of the electric motor 180 is compared with the state-typical Model signal form 240 is compared.
the feature "compare" should be interpreted broadly and in the sense of a signal analysis, so that a result of the comparison can in particular also be a partial or gradual agreement of the signal of the operating variable 200 of the electric motor 180 with the state-typical model signal form 240, wherein the degree of agreement of the two signals can be determined by various mathematical methods, which will be mentioned later.
step S1.3 the comparison is also used to determine a match assessment of the signal of the operating variable 200 of the electric motor 180 with the state-typical model signal form 240, thus making a statement about the match between the two signals.
the implementation and sensitivity of the match assessment are factory- or user-adjustable parameters for recognizing the application class.
Figure 7(b) shows a curve of a function q(x) of a signal of the operating variable 200 of the Figure 7(a) corresponding agreement evaluation 201, which indicates at each point of the abscissa x a value of the agreement between the signal of the operating variable 200 of the electric motor 180 and the state-typical model signal form 240.
this evaluation is used to determine the extent of further rotation in the event of an impact.
the state-typical model signal shape 240 predetermined in step S1.1 corresponds in the example to an ideal impact without further rotation, i.e. the state in which the head of the screw 900 rests on the surface of the fastening carrier 902, as in area 324 of the Figure 7(a) shown. Accordingly, in the area 324 there is a high level of agreement between the two signals, which is reflected by a consistently high value of the function q(x) of the agreement evaluation 201. In the area 310, however, in which each impact is accompanied by high angles of rotation of the screw 900, only small agreement values are achieved.
the application class is now at least partially recognized based on the match rating 201 determined in method step S1.3.
the recognition of the application class can, for example, be carried out at least partially based on a comparison of the match rating 201 with a threshold value which is Figure 7(b) is marked by a dashed line 202.
Figure 7(b) the intersection point SP of the function q(x) of the conformity assessment 201 with the line 202 is associated with the work progress of the resting of the head of the screw 900 on the surface of the fastening support 902.
the resulting criterion which is used to determine whether a particular application class exists, can be adjustable in order to make the function usable for a wide range of applications. It should be noted that the function is not only limited to screwing-in cases, but can also be used for unscrewing applications.
an application class can be identified and automatically selected by distinguishing between signal forms.
the method steps S1.2 and S1.3 are carried out repeatedly during the operation of a hand-held power tool 100 in order to monitor the presence of an application class.
the determined signal of the operating variable 200 can be segmented in method step S1.1, so that the method steps S1.2 and S1.3 are carried out on signal segments, preferably always of the same, fixed length.
the signal of the operating variable 200 can be stored as a sequence of measured values in a memory, preferably a ring buffer.
the hand-held power tool 100 comprises the memory, preferably the ring buffer.
the signal of the operating variable 200 is determined as a time course of measured values of the operating variable, or as measured values of the operating variable as a variable of the electric motor 180 that correlates with the time course.
the measured values can be discrete, quasi-continuous or continuous.
the signal of the operating variable 200 is recorded in method step S1.1 as a time profile of measured values of the operating variable and in a method step S1.1a following method step S1.1, a transformation of the time profile of the measured values of the operating variable into a profile of the measured values of the operating variable as a variable of the electric motor 180 that correlates with the time profile takes place, such as the angle of rotation of the tool holder 140, the angle of rotation of the motor, an acceleration, a jerk, in particular of a higher order, a power, or an energy.
Figure 8a Signals f(x) of an operating variable 200 over an abscissa x, in this case over time t.
the operating variable can be an engine speed or a parameter correlated with the engine speed.
the figure contains two signal curves of operating size 200, each of which can be assigned to an application class, for example a hard screwing case in the case of an impact wrench.
the signal comprises a wavelength of an oscillation curve that is ideally assumed to be sinusoidal, with the signal with a shorter wavelength, T1, having a curve with a higher impact frequency, and the signal with a longer wavelength, T2, having a curve with a lower impact frequency.
Both signals can be generated with the same hand-held power tool 100 at different motor speeds and depend, among other things, on the rotational speed requested by the user from the hand-held power tool 100 via the control switch.
the parameter "wavelength" is to be used to define the state-typical model signal form 240, then in the present case at least two different wavelengths T1 and T2 would have to be stored as possible parts of the state-typical model signal form so that the comparison of the signal of the operating variable 200 with the state-typical model signal form 240 leads to the result "match” in both cases. Since the engine speed can change generally and to a large extent over time, this means that the wavelength sought also varies and the methods for detecting this beat frequency would therefore have to be adjusted accordingly.
the time values of the abscissa are therefore transformed into values that correlate with the time values, such as acceleration values, higher order jerk values, power values, energy values, frequency values, rotation angle values of the tool holder 140 or Angle of rotation values of the electric motor 180.
the rigid transmission ratio of the electric motor 180 to the impact mechanism and the tool holder 140 results in a direct, known dependence of the motor speed on the impact frequency.
the state-typical model signal shape 240 can be defined valid for all rotational speeds by a single parameter of the wavelength over the time-correlated quantity, such as the angle of rotation of the tool holder 140, the motor angle of rotation, an acceleration, a jerk, in particular of a higher order, a power, or an energy.
the comparison of the signal of the operating variable 200 in method step S1.3 is carried out with a comparison method, wherein the comparison method comprises at least a frequency-based comparison method and/or a comparative comparison method.
the comparison method compares the signal of the operating variable 200 with the state-typical model signal shape 240 to determine whether at least one predetermined threshold value is met.
the comparison method compares the measured signal of the operating variable 200 with at least one predetermined threshold value.
the frequency-based comparison method comprises at least the bandpass filtering and/or the frequency analysis.
the comparative comparison method comprises at least the parameter estimation and/or the cross-correlation. The frequency-based and the comparative comparison method are described in more detail below.
the input signal is filtered via one or more bandpass filters whose passbands correspond to one or more state-typical model signal shapes.
the passband results from the state-typical model signal shape 240. It is also conceivable that the passband is connection with the state-typical model signal shape 240. In the event that amplitudes of this frequency exceed a previously defined limit value, as is the case when a certain application class is present, the comparison in method step S1.3 then leads to the result that the signal of the operating variable 200 is equal to the state-typical model signal shape 240 and that the application class to be recognized is therefore present.
the setting of an amplitude limit value can be understood in this embodiment as determining the agreement assessment of the state-typical model signal shape 240 with the signal of the operating variable 200, on the basis of which it is decided in method step S1.4 whether the application class to be recognized is present or not. If the application class to be recognized is not present, in a further step another state-typical model signal shape 240 assigned to a different application class can be compared with the signal of the operating variable. This can be carried out as long as necessary and cyclically until a certain application class is recognized.
Frequency analysis in this form is well known as a mathematical tool for signal analysis in many areas of technology and is used, among other things, to approximate measured signals as series expansions of weighted periodic harmonic functions of different wavelengths.
Figure 9(b) and 9(c) for example, weighting factors ⁇ 1 (x) and ⁇ 2 (x) are given as function curves 203 and 204 over time, whether and to what extent the corresponding frequencies or frequency bands, which are not indicated here for the sake of clarity, are present in the signal under investigation, i.e. the curve of the operating variable 200.
frequency analysis can be used to determine whether and with what amplitude the frequency assigned to the state-typical model signal shape 240 is present in the signal of the operating variable 200.
frequencies can also be defined whose absence is a measure of the presence of the work progress to be recognized.
a limit value of the amplitude can be set, which is a measure of the degree of agreement between the signal of the operating variable 200 and the state-typical model signal shape 240.
the joint presence of the limit values 203(a), 204(a) being exceeded or not being met by the amplitude functions ⁇ 1 (x) or ⁇ 2 (x) is the decisive criterion for the assessment of the conformity of the signal of the operating variable 200 with the state-typical model signal form 240. Accordingly, in this case, it is determined in method step S1.4 that the application class to be recognized is present.
the signal of the operating variable 200 is compared with the state-typical Model signal form 240 is compared to find out whether the measured signal of the operating variable 200 has at least a 50% match with the state-typical model signal form 240 and thus the predetermined threshold value is reached. It is also conceivable that the signal of the operating variable 200 is compared with the state-typical model signal form 240 to determine whether the two signals match each other.
the measured signal of the operating variables 200 is compared with the state-typical model signal form 240, wherein estimated parameters are identified for the state-typical model signal form 240.
estimated parameters a degree of agreement between the measured signal of the operating variables 200 and the state-typical model signal form 240 can be determined as to whether the application class to be recognized is present.
the parameter estimation is based on the adjustment calculation, which is a mathematical optimization method known to those skilled in the art.
the mathematical optimization method makes it possible to adjust the state-typical model signal form 240 to a series of measurement data of the signal of the operating variable 200.
the decision as to whether the application class to be recognized is present can be made.
a measure of the agreement of the estimated parameters of the state-typical model signal shape 240 to the measured signal of the operating variable 200 can also be determined.
a comparison determination is carried out in the method step S1.3 following method step S1.3a. If the comparison of the state-typical model signal form 240 with the measured signal of the operating variable of 70%, the decision can be made whether the application class to be recognized was identified based on the signal of the operating size.
a quality determination for the estimated parameters is carried out in a method step S1.3b following method step S1.3.
values for a quality between 0 and 1 are determined, whereby a lower value means a higher confidence in the value of the identified parameter and thus represents a higher agreement between the state-typical model signal form 240 and the signal of the operating variable 200.
the decision as to whether the application class to be recognized is present is made in the preferred embodiment in method step S1.4 at least partially based on the condition that the value of the quality is in a range of 50%.
the cross-correlation method is used as a comparative comparison method in method step S1.3.
the cross-correlation method is known per se to those skilled in the art.
the state-typical model signal shape 240 is correlated with the measured signal of the operating variable 200.
the result of the cross-correlation is again a signal sequence with an added signal length from a length of the signal of the operating variable 200 and the state-typical model signal form 240, which represents the similarity of the time-shifted input signals.
the maximum of this output sequence represents the time of the highest agreement between the two signals, i.e. the signal of the operating variable 200 and the state-typical model signal form 240, and is thus also a measure of the correlation itself, which in this embodiment is used in method step S1.4 as a decision criterion for the presence of the application class to be recognized.
a significant difference to the parameter estimation is that any state-typical Model signal shapes can be used, while in parameter estimation the state-typical model signal shape 240 must be able to be represented by parameterizable mathematical functions.
Figure 10 represents the measured signal of the operating quantity 200 in the case that frequency analysis is used as the frequency-based comparison method.
the first area 310 is shown, in which the hand tool 100 is in screwing mode.
the time t or a time-correlated quantity is plotted.
the signal of the operating variable 200 is shown transformed, whereby, for example, a fast Fourier transformation can be used to transform from a time domain to a frequency domain.
the frequency f is plotted so that the amplitudes of the signal of the operating variable 200 are shown.
Figure 10c and d the second region 320 is shown, in which the hand-held power tool 100 is in rotary impact mode.
Figure 10c shows the measured signal of the operating quantity 200 plotted over time in rotary impact operation.
Figure 10d shows the transformed signal of the operating variable 200, where the signal of the operating variable 200 is plotted against the frequency f as abscissa x'.
Figure 10d shows characteristic amplitudes for rotary impact operation.
Figure 11a shows a typical case of a comparison using the comparative comparison method of parameter estimation between the signal of an operating variable 200 and a state-typical model signal shape 240 in the first area 310 described in Figure 7. While the state-typical model signal shape 240 has an essentially trigonometric curve, the signal of the operating variable 200 has a curve that differs greatly from this. Regardless of the choice of one of the comparison methods described above, in this case the comparison carried out in method step S1.3 between the state-typical model signal shape 240 and the signal of the operating variable 200 results in the degree of agreement between the two signals being so low that the application class to be recognized is not recognized in method step S1.4.
Figure 12 shows the comparison of the state-typical model signal shape 240, see Figure 12b and 12e , with the measured signal of operating size 200, see Figure 12a and 12d , in case cross-correlation is used as a comparative comparison method.
the time or a value correlated with time is plotted on the abscissa x.
the first area 310 corresponding to the screwing operation, is shown.
the third area 324 corresponding to the application class to be recognized, is shown.
the measured signal of the operating variable, Figure 12a and Figure 12d with the state-typical model signal shape, Figure 12b and 12e , correlated.
the hand tool 100 is first connected to the app. The user is then asked via the app at 1302 whether In step S2 the second operating mode should be selected as standard.
model signal form 240 corresponding to the application class "hard screw joint” is provided by default at 1310 in process step 1.2.
the model signal form 240 corresponding to the application class "hard screw joint" is only provided at 1310 in method step 1.2 and stored as an application class to be recognized if the user explicitly specifies this for a specific application in 1308.
step S2 the screwing process is operated with a reduced maximum torque.
the following applications always inform the user that the second operating mode is active and can be deactivated via a corresponding menu if necessary.
the second operating mode is selected again in step S2 at 1328 after the machine has been used once.

Landscapes

Engineering & Computer Science (AREA)
Mechanical Engineering (AREA)
Control Of Electric Motors In General (AREA)
Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)

EP23203789.5A 2022-11-08 2023-10-16 Procédé d'opération d'une machine-outil portative Pending EP4368346A1 (fr)

Applications Claiming Priority (1)

Application Number	Priority Date	Filing Date	Title
DE102022210619.9A DE102022210619A1 (de)	2022-11-08	2022-11-08	Verfahren zum Betrieb einer Handwerkzeugmaschine

Publications (1)

Publication Number	Publication Date
EP4368346A1 true EP4368346A1 (fr)	2024-05-15

Family

ID=88417606

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
EP23203789.5A Pending EP4368346A1 (fr)	2022-11-08	2023-10-16	Procédé d'opération d'une machine-outil portative

Country Status (4)

Country	Link
US (1)	US20240149411A1 (fr)
EP (1)	EP4368346A1 (fr)
CN (1)	CN118003276A (fr)
DE (1)	DE102022210619A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
DE202017003590U1 (de)	2016-09-28	2017-08-29	Makita Corporation	Elektrisch angetriebenes Werkzeug
EP3228423A1 (fr) *	2016-04-06	2017-10-11	HILTI Aktiengesellschaft	Comportement de commutation optimise par application d'un dispositif d'accouplement a patinage electronique
EP3381615A1 (fr)	2017-03-23	2018-10-03	Makita Corporation	Outil de fixation à impact
DE102020124812A1 (de) *	2019-09-27	2021-04-01	Makita Corporation	Elektrokraftwerkzeug
DE102019215417A1 (de) *	2019-10-09	2021-04-15	Robert Bosch Gmbh	Verfahren zum Betrieb einer Handwerkzeugmaschine

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
DE102019204071A1 (de) *	2019-03-25	2020-10-01	Robert Bosch Gmbh	Verfahren zur Erkennung eines ersten Betriebszustandes einer Handwerkzeugmaschine
DE102020211889A1 (de) *	2020-09-23	2022-03-24	Robert Bosch Gesellschaft mit beschränkter Haftung	Handwerkzeugmaschine
DE102020215988A1 (de) *	2020-12-16	2022-06-23	Robert Bosch Gesellschaft mit beschränkter Haftung	Verfahren zum Betrieb einer Handwerkzeugmaschine

2022
- 2022-11-08 DE DE102022210619.9A patent/DE102022210619A1/de active Pending
2023
- 2023-10-16 EP EP23203789.5A patent/EP4368346A1/fr active Pending
- 2023-10-30 US US18/496,993 patent/US20240149411A1/en active Pending
- 2023-11-08 CN CN202311486587.7A patent/CN118003276A/zh active Pending

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
EP3228423A1 (fr) *	2016-04-06	2017-10-11	HILTI Aktiengesellschaft	Comportement de commutation optimise par application d'un dispositif d'accouplement a patinage electronique
DE202017003590U1 (de)	2016-09-28	2017-08-29	Makita Corporation	Elektrisch angetriebenes Werkzeug
EP3381615A1 (fr)	2017-03-23	2018-10-03	Makita Corporation	Outil de fixation à impact
DE102020124812A1 (de) *	2019-09-27	2021-04-01	Makita Corporation	Elektrokraftwerkzeug
DE102019215417A1 (de) *	2019-10-09	2021-04-15	Robert Bosch Gmbh	Verfahren zum Betrieb einer Handwerkzeugmaschine

Also Published As

Publication number	Publication date
DE102022210619A1 (de)	2024-06-06
CN118003276A (zh)	2024-05-10
US20240149411A1 (en)	2024-05-09

Publication	Publication Date	Title
EP3946818B1 (fr)	2024-09-25	Procédé de reconnaissance d'un premier état de fonctionnement d'une machine-outil portative
DE102019211303A1 (de)	2021-02-04	Verfahren zur Erkennung eines Arbeitsfortschrittes einer Handwerkzeugmaschine
DE102019211305A1 (de)	2021-02-04	Verfahren zum Betrieb einer Handwerkzeugmaschine
DE102011104901B4 (de)	2018-04-12	Kraftgetriebene Handwerkzeugmaschine
DE102019215417A1 (de)	2021-04-15	Verfahren zum Betrieb einer Handwerkzeugmaschine
EP3113911B1 (fr)	2018-05-02	Affichage de puissance adaptatif
EP4041496B1 (fr)	2024-07-10	Procédé d'apprentissage d'arrêts d'applications par la recherche de formes de signaux caractéristiques
DE3331793A1 (de)	1984-03-08	Einrichtung zum feststellen von werkzeugabnutzung
DD252287A3 (de)	1987-12-16	Verfahren zum anziehen oder loesen schraubbarer verbindungen
DE202014009989U1 (de)	2015-01-16	Oszillationswerkzeugmaschine
WO2022084003A1 (fr)	2022-04-28	Procédé de commande d'outil électrique portatif
EP2874547B1 (fr)	2016-04-27	Dispositif et procédé de commande d'entraînement d'un système chirurgical à moteur
EP4263137A1 (fr)	2023-10-25	Procédé de fonctionnement d'un outil électrique portatif
EP4368346A1 (fr)	2024-05-15	Procédé d'opération d'une machine-outil portative
EP4406701A1 (fr)	2024-07-31	Procédé de fonctionnement d'une machine-outil portative
EP2888811B1 (fr)	2017-01-18	Procédé et dispositif de réglage d'un moteur électrique de machine-outil portative
EP4406700A1 (fr)	2024-07-31	Procédé de fonctionnement d'une machine-outil portative
DE102023200617A1 (de)	2024-08-01	Verfahren zum Steuern einer Handwerkzeugmaschine und Handwerkzeugmaschine
DE102023200607A1 (de)	2024-08-01	Verfahren zum Steuern einer Handwerkzeugmaschine und Handwerkzeugmaschine
EP3854556B1 (fr)	2024-03-06	Procédé de fonctionnement d'un appareil d'usinage guidé à la main et appareil d'usinage guidé à la main
EP2062547A1 (fr)	2009-05-27	Instrument dentaire à ultrasons et procédé de fonctionnement d'un instrument dentaire à ultrasons
EP4406704A2 (fr)	2024-07-31	Procédé de création d'un ensemble de données d'entraînement, procédé d'entraînement d'une intelligence artificielle, intelligence artificielle et machine-outil manuelle
DE102023200615A1 (de)	2024-08-01	Verfahren zum Auswählen von Daten für ein Training einer künstlichen Intelligenz, Verfahren zum Erzeugen eines Trainingsdatensatzes, Trainingsdatensatz
DE102023200608A1 (de)	2024-08-01	Verfahren zum Steuern einer Handwerkzeugmaschine und Handwerkzeugmaschine
DE102023200604A1 (de)	2024-08-01	Verfahren zum Steuern einer Handwerkzeugmaschine und Handwerkzeugmaschine

Legal Events

Date	Code	Title	Description
2024-04-12	PUAI	Public reference made under article 153(3) epc to a published international application that has entered the european phase	Free format text: ORIGINAL CODE: 0009012
2024-04-12	STAA	Information on the status of an ep patent application or granted ep patent	Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED
2024-05-15	AK	Designated contracting states	Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR
2024-11-22	STAA	Information on the status of an ep patent application or granted ep patent	Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE
2024-12-25	17P	Request for examination filed	Effective date: 20241115
2024-12-25	RBV	Designated contracting states (corrected)	Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR