Method for Operating a Hand-Guided Working Apparatus, and Hand-Guided Working Apparatus

Abstract

A method operates a hand-guided working apparatus having a movable working tool installation, a shaft, and a drive motor system. The shaft is designed for moving the working tool installation. The drive motor system is designed for driving the shaft. The working tool installation, the shaft, and the drive motor system at least in part form part of a system capable of rotational oscillation. A controllable oscillation damping installation is designed for damping and/or reducing an excitation of at least one oscillation of the system capable of rotational oscillation and/or excitable by the system capable of rotational oscillation. The method includes: operating the drive motor system to drive the shaft for moving the working tool installation; and controlling the oscillation damping installation during operation such that the oscillation is at least damped and/or an excitation of the oscillation is reduced.

Claims

1. A method for operating a hand-guided working apparatus, wherein the working apparatus comprises: a movable working tool installation; a shaft, wherein the shaft is designed for moving the working tool installation; a drive motor system, wherein the drive motor system is designed for driving the shaft; wherein the working tool installation, the shaft and the drive motor system at least in part form at least one part of a system capable of rotational oscillation; and a controllable oscillation damping installation, wherein the oscillation damping installation is designed at least for damping and/or reducing an excitation of at least one oscillation of the system capable of rotational oscillation and/or excitable by the system capable of rotational oscillation; wherein the method comprises the steps of: a) operating the drive motor system for driving the shaft for moving the working tool installation; and b) controlling the oscillation damping installation during operation in such a manner that the oscillation is at least damped and/or an excitation of the oscillation is reduced.

2. The method according to claim 1, wherein the working apparatus is a cutting apparatus; and/or the working tool installation is a cutting tool installation.

3. The method according to claim 1, wherein the working apparatus has a gearbox, wherein the gearbox is designed for moving the working tool installation, and wherein the shaft is designed for moving the gearbox, and/or wherein the gearbox is designed for driving the shaft, and wherein the drive motor system is designed for driving the gearbox; and wherein the gearbox at least in part forms a part of the system capable of rotational oscillation.

4. The method according to claim 1, wherein the working apparatus has a shank; wherein the shaft is disposed in the shank; and wherein the working tool installation and the drive motor system are mechanically connected to one another by way of at least the shank, including the system capable of rotational oscillation being mechanically closed by way of at least the shank.

5. The method according to claim 4, wherein the working apparatus has at least one handle; wherein the at least one handle is disposed in a region of the shaft so as to be between ends of the shaft.

6. The method according to claim 1, wherein the oscillation damping installation has at least one actuator, wherein the at least one actuator is designed at least for damping and/or for reducing an excitation at least of the oscillation, and wherein step b) comprises: controlling the at least one actuator in such a manner that the oscillation is at least damped and/or an excitation of the oscillation is avoided.

7. The method according to claim 1, wherein the drive motor system and the oscillation damping installation are completely different.

8. The method according to claim 6, wherein the drive motor system has an internal combustion drive engine designed for driving the shaft; and wherein step a) comprises: operating the internal combustion drive engine to drive the shaft for moving the working tool installation.

9. The method according to claim 1, wherein the drive motor system and the oscillation damping installation are at least partially integrated.

10. The method according to claim 9, wherein the drive motor system has an electric drive motor designed for driving the shaft, and wherein the drive motor system having the electric drive motor and the oscillation damping installation are at least partially integrated; and wherein step a) comprises: operating the electric drive motor to drive the shaft for moving the working tool installation; and further wherein step a) and/or step b) comprises: operating and/or controlling the electric drive motor in such a manner that the oscillation is at least damped and/or an excitation of the oscillation is reduced.

11. The method according to claim 10, wherein the oscillation damping installation has a notch filter; and wherein step a) and/or step b) comprises: operating and/or controlling the electric drive motor while using the notch filter by filtering a frequency component, that excites at least the oscillation, from a variable signal in the form of a nominal torque signal, a nominal current signal and/or a feedback variable signal, of an electronic motor control unit of the drive motor system.

12. The method according to claim 1, wherein the method further comprises the step of: detecting at least one actual oscillation of the system capable of rotational oscillation and/or excited by the system capable of rotational oscillation during step a) and/or temporally before step b) and/or during step b); and wherein step b) comprises: controlling based at least on the detected actual oscillation.

13. The method according to claim 12, wherein the method further comprises: detecting at least the actual oscillation by way of the oscillation damping installation and/or the drive motor system, by detecting a temporal actual operating data profile, of the drive motor system.

14. The method according to claim 1, wherein the shaft has a length of at least 0.5 m, and/or of at most 4.5 m; and/or wherein the oscillation has a frequency of at least 2 Hz, and/or of at most 100 Hz.

15. The method according to claim 2, wherein the cutting apparatus is a brushcutter or an edge trimmer; and/or wherein the cutting tool installation comprises a cutting line, a cutting knife or a cutting blade.

16. The method according to claim 5, wherein the at least one handle is fastened to the shank.

17. The method according to claim 6, wherein the at least one actuator is a solenoid and/or a linear actuator.

18. The method according to claim 11, wherein the electronic motor control unit of the drive motor system is an electronic closed-loop motor control unit.

19. The method according to claim 13, wherein the detected temporal actual operating data profile is a temporal actual rotating speed and/or current and/or voltage and/or power profile, of the drive motor system.

20. A hand-guided working apparatus, comprising: a movable working tool installation; a shaft, wherein the shaft is designed for moving the working tool installation; a drive motor system, wherein the drive motor system is designed for driving the shaft; wherein the working tool installation, the shaft and the drive motor system at least in part form at least one part of a system capable of rotational oscillation; a controllable oscillation damping installation, wherein the oscillation damping installation is designed at least for damping and/or for reducing an excitation of at least one oscillation of the system capable of rotational oscillation and/or excitable by the system capable of rotational excitation; and an operating and controlling installation, wherein the operating and controlling installation is designed to: operate the drive motor system for driving the shaft for moving the working tool installation; and control the oscillation damping installation during operation in such a manner that the oscillation is at least damped and/or an excitation of the oscillation is reduced.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 schematically shows a hand-guided working apparatus according to an embodiment of the invention in the form of a brushcutter, having a cutting line, and a method according to an embodiment of the invention for operating the hand-guided working apparatus;

[0035] FIG. 2 schematically shows a further hand-guided working apparatus in the form of an edge trimmer, having a cutting knife, and the method for operating the hand-guided working apparatus;

[0036] FIG. 3 schematically shows details of the respective working apparatus of FIGS. 1 and 2;

[0037] FIG. 4 schematically shows a graph of a respective rotational oscillation, in particular of an amplitude of an acceleration over a frequency, of the respective working apparatus of FIGS. 1 and 2, having a rigid shaft or a flexible shaft, without controlling an oscillation damping installation of the respective working apparatus of the method;

[0038] FIG. 5 schematically shows a graph of a respective flexural oscillation, in particular of an amplitude of a deflection over a frequency, of the respective working apparatus of FIGS. 1 and 2, having the flexible shaft, without controlling a oscillation damping installation of the respective working apparatus of the method;

[0039] FIG. 6 schematically shows detecting an actual oscillation of the respective working apparatus of FIGS. 1 and 2 of the method, in particular a graph of a temporal actual rotating speed profile of a drive motor system of the working apparatus over time; and

[0040] FIG. 7 schematically shows yet a further hand-guided working apparatus and the method for operating the hand-guided working apparatus.

DETAILED DESCRIPTION OF THE DRAWINGS

[0041] FIGS. 1, 2, 3 and 7, in particular each, show a hand-guided working apparatus 1. The working apparatus 1 has a movable working tool installation 2, a shaft 3, a drive motor system 4, a controllable oscillation damping installation 6, and an operating and controlling installation 15. The shaft 3 is designed, in particular moved, for moving the working tool installation 2. The drive motor system 4 is designed for driving the shaft 3 and in particular drives the latter. The working tool installation 2, the shaft 3, and the drive motor system 4 form at least in part at least one part of a system 5 at least capable of rotational vibrating. The oscillation damping installation 6 is designed at least for damping and/or for reducing, in particular avoiding, an excitation of at least one oscillation RS of the system 5 capable of rotational oscillation, and/or excitable by the system 5 capable of rotational oscillation, as is shown in FIGS. 4 and 5, in particular damping and/or reducing, in particular avoiding said oscillation RS. The operating and controlling installation 15 is designed for operating the drive motor system 4 for driving the shaft 3 for moving the working tool installation 2, and for controlling the oscillation damping installation 6 during the operation in such a manner that the oscillation RS is at least damped and/or an excitation of the oscillation RS is reduced, in particular avoided; said operating and controlling installation 15 in particular operating and controlling the drive motor system 4.

[0042] FIGS. 1, 2, 3, 6 and 7 show a method for operating the hand-guided working apparatus 1. The working apparatus 1 has the movable working tool installation 2, the shaft 3, the drive motor system 4, and the controllable oscillation damping installation 6. The shaft 3 is designed for moving the working tool installation 2. The drive motor system 4 is designed for driving the shaft 3. The working tool installation 2, the shaft 3, and the drive motor system 4 form at least in part the at least one part of the system 5 at least capable of rotational oscillation. The oscillation damping installation 6 is designed at least for damping and/or for reducing, in particular avoiding, an excitation of the at least one oscillation RS of the system 5 capable of rotational oscillation, and/or excitable by the system 5 capable of rotational oscillation. The method comprises the steps: a) operating the drive motor system 4 for driving the shaft 3 for moving the working tool installation 2, in particular by means of the operating and controlling installation 15; b) controlling the oscillation damping installation 6 during operation in such a manner that the oscillation RS is at least damped and/or an excitation of the oscillation RS is reduced, in particular avoided, in particular by means of the operating and controlling installation 15.

[0043] In the exemplary embodiments shown, the working apparatus 1 is a cutting apparatus 1′, in particular a brushcutter 1″, as is shown in FIG. 1, or an edge trimmer 1′″, as is shown in FIG. 2.

[0044] In alternative exemplary embodiments, the cutting apparatus can be a pole-mounted pruner or a hedge trimmer.

[0045] Additionally or alternatively, the working tool installation 2 in the exemplary embodiments shown is a cutting tool installation 2′; the working tool installation 2 has in particular a cutting line 2″, as is shown in FIG. 1, or a cutting knife 2′″, as is shown in FIG. 2.

[0046] The working apparatus 1 furthermore has a gearbox 7. The gearbox is designed, in particular moved, for moving the working tool installation 2, and the shaft 3 is designed, in particular moved, for moving the gearbox 7, as is shown in FIG. 2. Alternatively, the gearbox 7 is designed for driving the shaft 3, in particular driving the latter, and the drive motor system 4 is designed for driving the gearbox 7, in particular driving the latter, as is shown in FIG. 1. The gearbox 7 at least in part forms a part of the system 5 capable of rotational oscillation.

[0047] The working apparatus 1 moreover has a shank 8. The shaft 3 is disposed in the shank 8. The working tool installation 2 and the drive motor system 4 are mechanically connected to one another by means of at least the shank 8. In particular, the system 5 capable of rotational oscillation is mechanically closed by means of at least the shank 8.

[0048] The working apparatus 1 furthermore has at least one handle 9. The at least one handle 9 is disposed in the region of the shaft 3, so as to be between ends 3E of the shaft 3, in particular fastened to the shank 8.

[0049] The shaft 3 moreover has a length 3 L of at least 0.5 m, in particular of at least 1 m, and/or of at most 4.5 m, in particular of at most 3 m, in particular of 1.5 m, in particular in a direction z.

[0050] Additionally or alternatively, the oscillation RS has a frequency fS, in particular a natural frequency and/or resonance frequency, of at least 2 Hz, in particular of at least 5 Hz, in particular of at least 10 Hz, and/or of at most 100 Hz, in particular of at most 50 Hz, as is shown in FIGS. 4 and 5.

[0051] Specifically, the oscillation RS is a rotational oscillation of the system 5 capable of rotational oscillation, in particular about a longitudinal axis 3A of the shaft 3, or about the direction z, as is shown in FIG. 4.

[0052] If the shaft 3 is a rigid shaft, the oscillation RS in the form of the rotational oscillation has the frequency fS of, for example, 41.75 Hz, as is shown in FIG. 4, in particular a graph of an amplitude of an acceleration, in particular of the gearbox 7 of the exemplary embodiment of FIG. 2, initiated by the oscillation RS in the form of the rotational oscillation, in a direction y orthogonal to the longitudinal axis 3A of the shaft 3, or the direction z, over a frequency. If the shaft 3 is a flexible shaft, the oscillation RS in the form of the rotational oscillation has the frequency fS of, for example, 12.45 Hz.

[0053] The frequency fS of the oscillation RS in the form of the rotational oscillation is determined by an, in particular respective, inertia of the working tool installation 2 (J2) and of the drive motor system 4 (J4), a transmission ratio of the gearbox 7 (ü7) and a rigidity of the shaft 3 (C3), in particular as follows:

[00001]$\mathrm{fS}*2\pi =\sqrt{\frac{C3*\left(\left(J4+\stackrel{\mathrm{.Math.}}{u}{7}^2\right)+J2\right)}{J4*J2}}$

[0054] In the exemplary embodiments shown, the system 5 at least capable of rotational oscillation, in particular the shaft 3 and the shank 8, are additionally capable of flexural oscillation.

[0055] In particular, the shank 8 at least in part forms a part of the system 5 capable of rotational oscillation and capable of flexural oscillation.

[0056] Specifically, the oscillation RS is a flexural oscillation of the system 5 at least capable of rotational oscillation, in particular of the shaft 3 and of the shank 8, and excitable, in particular by means of a structure of the working apparatus 1, by the rotational oscillation of the system 5 capable of rotational oscillation, in particular in a direction x orthogonal to the longitudinal axis 3A of the shaft 3, or the direction z and/or the direction y, as is shown in FIG. 4, in particular if the shaft 3 is the flexible shaft.

[0057] In particular if the shaft 3 is the flexible shaft, the oscillation RS in the form of the flexural oscillation has the frequency fS of, for example, 12.45 Hz, as is shown in FIG. 5, in particular a graph of an amplitude of a deflection initiated by the oscillation RS in the form of the flexural oscillation, in particular of the handle 9, in the direction x orthogonal to the longitudinal axis 3A of the shaft 3, or the direction z and/or the direction y, over a frequency.

[0058] The control of the oscillation damping installation 6 during operation enables the oscillation RS to be at least damped and/or an excitation of the oscillation RS to be reduced, in particular avoided.

[0059] Specifically, the oscillation damping installation 6 in the exemplary embodiment of FIG. 7 has at least one actuator 10, in particular at least one solenoid 10′ and/or a linear actuator 10″. The at least one actuator 10 is at least designed for damping and/or for reducing, in particular avoiding, an excitation at least of the oscillation RS, in particular damping and/or reducing, in particular avoiding, the latter. Step b) comprises: controlling the at least one actuator 10 in such a manner that the oscillation RS is at least damped and/or an excitation of the oscillation RS is reduced, in particular avoided, in particular by means of the operating and controlling installation 15.

[0060] Moreover, the drive motor system 4 and the oscillation damping installation 6 in the exemplary embodiment of FIG. 7 are completely different from one another.

[0061] The drive motor system 4 in the exemplary embodiment of FIG. 7 furthermore has an internal combustion drive engine 11. The internal combustion drive engine 11 is designed for driving, in particular drives, the shaft 3. Step a) comprises: operating the internal combustion drive engine 11 for driving the shaft 3 for moving the working tool installation 2, in particular by means of the operating and controlling installation 15.

[0062] Moreover, the drive motor system 4 and the oscillation damping installation 6 in the exemplary embodiments of FIGS. 1, 2, and 3 are at least partially integrated.

[0063] The drive motor system 4 in the exemplary embodiments of FIGS. 1, 2, and 3 furthermore has an electric drive motor 12. The electric drive motor 12 is designed for driving, in particular drives, the shaft 3. In particular, the drive motor system 4 having the electric drive motor 12, and the oscillation damping installation 6 are at least partially integrated. Step a) comprises: operating the electric drive motor 12 for driving the shaft 3 for moving the working tool installation 2, in particular by means of the operating and controlling installation 15. Step a) and/or step b) comprise/comprises in particular: controlling and/or operating the electric drive motor 12 in such a manner that the oscillation RS is at least damped and/or an excitation of the oscillation RS is reduced, in particular avoided, in particular by means of the operating and controlling installation 15.

[0064] Specifically, the oscillation damping installation 6 has a notch filter 13, as is shown in FIG. 3. Step a) and/or step b) comprise/comprises: operating and/or controlling the electric drive motor 12 while using the notch filter 13, in particular by means of filtering a frequency component fK, in particular of the natural frequency and/or the resonance frequency fS of the oscillation RS, that excites at least the oscillation RS, as in shown in FIG. 4, from a variable signal GS of an electronic motor control unit 14, in particular an electronic closed-loop motor control unit 14′, in FIG. 3 in the form of a cascade control, of the drive motor system 4.

[0065] In the exemplary embodiments shown, filtering takes place from the variable signal GS in the form of a nominal torque signal SM, in particular while using the notch filter 13 at an output of a rotating speed controller of the electronic closed-loop motor control unit 14′. In alternative exemplary embodiments, filtering can take place from the variable signal GS in the form of a nominal current signal SI or a feedback variable signal RGS.

[0066] The electronic motor control unit 14 is in particular designed for controlling, the electronic closed-loop motor control unit 14′ in particular for controlling in a closed loop, a torque M generated by the drive motor system 4, in particular the electric drive motor 12, for achieving an in particular temporally constant nominal rotating speed Sn, in particular for controlling, in particular controlling in a closed loop, the latter.

[0067] The nominal rotating speed Sn can be achieved in a state of the working apparatus 1, in particular of the drive motor system 4, in particular of the electric drive motor 12, without load.

[0068] Since the frequency fS of the oscillation RS may lie in a dynamic range of the rotating speed controller, this meaning that the oscillation RS can be excited by the electronic rotating speed controller, the notch filter 13 enables the damping and/or the reduction, in particular the avoidance, of an excitation of the oscillation RS.

[0069] The method can be referred to as electric, in particular electronic, and/or controlled, in particular closed-loop controlled, oscillation damping.

[0070] The method moreover comprises the step: detecting at least one actual oscillation IS of the system 5 capable of rotational oscillation and/or excited by the system 5 capable of rotational oscillation, in particular during step a) and/or temporally before step b), and/or during step b), as is shown in FIG. 6. Step b) comprises: controlling based on at least the detected actual oscillation IS.

[0071] The detection in the exemplary embodiment of FIG. 7 is carried out by means of at least one sensor 16 of the working apparatus 1.

[0072] The sensor 16 is in particular disposed, in particular fastened, in the region of the working tool installation 2 and/or an, in particular lower and/or first, end, in particular at the end, of the shaft 3 or of the shank 4, and/or in the region of the shaft 3, so as to be between the ends 3E, in particular in the centre, of the shaft 3, in particular on the shank 8.

[0073] Additionally or alternatively, the sensor 16 can be a rotating speed sensor, in particular for detecting an actual rotating speed, in particular on the tool, in the region of the working tool installation 2, in particular of the working tool installation 2.

[0074] Furthermore additionally or alternatively, the detection in the other exemplary embodiments, in particular of FIGS. 1, 2, and 3, can also be carried out by means of the at least one sensor 16 of the working apparatus 1.

[0075] The actual rotating speed on the tool and an actual rotating speed on the motor, in particular of the drive motor system 4, in particular of the electric drive motor 12, in particular, and a position signal can thus be available. The oscillation RS can thus at least be actively damped, and/or an excitation of the oscillation RS be actively reduced, in particular actively avoided, by the drive motor system 4 having the electric drive motor 12, in particular, and the electronic closed-loop motor control unit 14′, and the oscillation damping installation 6 at least partially integrated, in particular by means of the operating and controlling installation 15.

[0076] The method shown in the exemplary embodiments of FIGS. 1, 2, and 3 comprises: detecting at least the actual oscillation IS by means of the oscillation damping installation 6 and/or the drive motor system 4, in particular by means of detecting a temporal actual operating data profile ID of the drive motor system 4, in particular without the sensor 16.

[0077] In the exemplary embodiments shown, the temporal actual operating date profile ID is detected in the form of a temporal actual rotating speed profile In. In alternative exemplary embodiments, the temporal actual operating data profile can be detected in the form of a temporal actual current and/or voltage and/or power profile.

[0078] As is shown in FIG. 6, the temporal operating data profile ID, in particular in the form of the temporal actual rotating speed profile In, in the case of what should be temporally constant actual operating data, in particular because the nominal operating data should be temporally constant, in particular in the case of what should be a temporally constant actual rotating speed, in particular because the nominal rotating speed Sn should be temporally constant, at, for example, 5000 revolutions per minute (rpm) or 10,000 rpm, has the actual oscillation IS, in particular having the frequency IS, which is in particular independent of the rotating speed, in particular, and an amplitude of several 100 rpm.

[0079] In alternative exemplary embodiments, the temporal operating data profile, in particular the rotating speed, in particular of the working tool installation, can also be estimated without a sensor by a so-called “monitor”.

[0080] As is highlighted by the exemplary embodiments shown and explained above, the invention provides an advantageous method for operating a hand-guided working apparatus, and an advantageous hand-guided working apparatus, each having improved properties, enabling in particular a high level of comfort for a user of the working apparatus.