Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D11/00—Portable percussive tools with electromotor or other motor drive
  • B25D11/06—Means for driving the impulse member
  • B25D11/064—Means for driving the impulse member using an electromagnetic drive
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D17/00—Details of, or accessories for, portable power-driven percussive tools
  • B25D17/24—Damping the reaction force
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D17/00—Details of, or accessories for, portable power-driven percussive tools
  • B25D17/24—Damping the reaction force
  • B25D17/245—Damping the reaction force using a fluid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2217/00—Details of, or accessories for, portable power-driven percussive tools
  • B25D2217/0073—Arrangements for damping of the reaction force
  • B25D2217/0076—Arrangements for damping of the reaction force by use of counterweights
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2217/00—Details of, or accessories for, portable power-driven percussive tools
  • B25D2217/0073—Arrangements for damping of the reaction force
  • B25D2217/0076—Arrangements for damping of the reaction force by use of counterweights
  • B25D2217/008—Arrangements for damping of the reaction force by use of counterweights being electronically-driven
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2217/00—Details of, or accessories for, portable power-driven percussive tools
  • B25D2217/0073—Arrangements for damping of the reaction force
  • B25D2217/0076—Arrangements for damping of the reaction force by use of counterweights
  • B25D2217/0084—Arrangements for damping of the reaction force by use of counterweights being fluid-driven
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2250/00—General details of portable percussive tools; Components used in portable percussive tools
  • B25D2250/141—Magnetic parts used in percussive tools
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2250/00—General details of portable percussive tools; Components used in portable percussive tools
  • B25D2250/141—Magnetic parts used in percussive tools
  • B25D2250/145—Electro-magnetic parts

Definitions

• the invention relates to a hand tool, in particular a percussion hammer, hammer drill or an electric chisel.
• the hand tool has a striking mechanism.
• the hand tool has a tool holder operatively connected to the striking mechanism.
• the tool holder is preferably designed to receive a tool, for example a chisel, in particular separable.
• the hand tool has a counteroscillator, wherein the counteroscillator is designed to at least partially compensate for a force generated by the striking mechanism along a striking axis, in particular by a reciprocating movement.
• the hand tool in the case of an air spring impact drive with an eccentric, wherein the eccentric is coupled to a working piston.
• the drive drives in the case of a hand tool with a counter-oscillator and the counter-oscillator, which is reciprocated by means of the drive along a translation axis and is moved by the reciprocating out of phase to a reciprocating motion of the working piston and thus a pulse of Working piston can at least partially compensate.
• the hand tool of the type mentioned in the introduction has at least one eddy current generator and one movably mounted along a translation axis and connected to the counteroscillator - or by means of the Counteroscillator formed - eddy current receiver on.
• the eddy current generator is preferably designed to generate a magnetic pulse in such a way that an eddy current can be generated in the eddy current receiver, and the eddy current receiver can generate a counter magnetic pulse in opposition to the eddy current and thus be repelled by the eddy current generator and along the translation axis Force can generate at least partially compensating counter-movement.
• the counteroscillator By means of the counter-oscillator driven by means of the eddy current generator, the counteroscillator can advantageously be driven mechanically decoupled from the impact mechanism.
• a drive and a phase control of the counter-oscillator can advantageously be controlled by a control unit in dependence on at least one sensor signal.
• the eddy current receiver is formed in particular as a whole by the counteroscillator, or the counteroscillator has the eddy current receiver.
• the eddy current receiver can be formed, for example, by a plate which is in particular highly conductive, for example copper or aluminum, the plate being connected to the counteroscillator, for example a preferably cylindrically shaped iron or steel weight.
• a counter-oscillator formed as a whole is, for example, in particular formed in one piece of ferromagnetic material, for example iron or steel.
• the striking mechanism is designed as an eddy current impact mechanism.
• the percussion mechanism preferably has a percussion eddy current receiver arranged in the detection region of the eddy current generator, preferably in the form of a firing pin or an armature designed to be operably connectable with a tool.
• the percussion mechanism has a percussion eddy current receiver arranged in the detection range of the eddy current generator in the form of a tool.
• the eddy current generator is preferably designed to generate a magnetic pulse in such a way that an eddy current can be generated in the percussion eddy current receiver, and the percussion eddy current receiver can generate a counterelectromagnetic pulse counter to the magnetic pulse as a function of the eddy current, so that the percussion eddy current receiver of be repelled the eddy current generator and can produce a blow along the striking axis.
• the tool in the form of a percussion eddy current receiver preferably has an electrically particularly well conductive plate arranged in the area of action of the percussion eddy current generator.
• the electrically conductive plate is formed, for example, of copper or aluminum. Due to the so-formed eddy current striking mechanism the striking mechanism advantageously needs less moving parts than a pneumatic spring percussion. Also conceivable is an integrally formed tool as a vortex flow receiver, which is formed for example of iron or steel.
• the translation axis of the counter-oscillator and the striking axis are coaxial with each other.
• the hand tool is formed, the
• Counter-oscillator and the tool with the same magnetic pulse to drive This can advantageously be saved an eddy current generator. Further advantageously, the same eddy current generator for driving the counter-oscillator and the tool.
• the hand tool is designed to attract the particular ferromagnetically formed counter-oscillator by means of a magnetic pulse and to move back to an initial position.
• the striking mechanism and / or the tool is designed to transfer at least part of the impact energy of the impact into a rotational movement of the tool about the striking axis.
• the hammer mechanism can preferably have the tool for this purpose.
• the tool in particular a chisel, can have, for example, in a region which is designed in particular for receiving a magnetic pulse and for generating the eddy current, a surface which is helically formed along the striking axis.
• a magnetic field distribution is advantageously formed to repel the Schlagwerk eddy current receiver from the eddy current generator, which transmits an angular momentum during ejection from the eddy current generator, the eddy current receiver and preferably additionally the tool.
• the eddy current generator has a flat coil whose coil windings extend with a winding radius which increases radially outward from the striking axis.
• the coil windings of the flat coil are formed of stranded wire.
• the coil in particular due to a skin effect, can generate the magnetic pulse particularly efficiently.
• the coil windings of the flat coil extend helically in a longitudinal section along the striking axis such that the tool can perform a rotational movement about the striking axis in addition to a translation movement along the striking axis.
• the tool can additionally carry out a drilling movement at least in sections in the circumferential direction of rotation.
• the percussion eddy current receiver in particular a firing pin or the tool, may be formed in the region of one end with a flat surface, which is located in the effective range of the eddy current generator and which faces the eddy current generator. Further advantageously, an angular momentum can be transmitted to the tool by the flat coil thus formed, so that the tool can also perform a rotational movement in addition to a striking movement.
• the flat coil is connected to generate the magnetic pulse with a capacitor.
• the flat coil and the capacitor form electromagnetically a resonant circuit. As a result, the magnetic pulse can be generated particularly efficiently.
• the striking mechanism is an air spring impact mechanism.
• a hand tool with an air spring impact mechanism can advantageously be provided with the counteroscillator in a particularly cost-effective manner by means of a vortex-driven counter-oscillator.
• the counteroscillator is connected by means of an air spring with the tool and can generate a vibration together with the tool via the air spring.
• a lumen enclosed by a counteroscillator receptacle more preferably via a lumen, can be used.
• a tube connected to a lumen enclosed by the tool holder.
• the tool is in resonance with the counteroscillator via the lumen or additionally via the lumen of the tube.
• the hand tool preferably has a handle with which the hand tool can be held by an adult hand or with two hands.
• the invention also relates to a method for operating a hand tool which is at least hammering, preferably additionally drilling, in which a pulse of a shock acting on a tool is at least partially compensated by means of a counter-oscillator, wherein a magnetic pulse is generated as a function of an excitation current and as a function thereof An eddy current is generated in the counter-oscillator of the magnetic pulse, wherein the eddy current generates a counter-magnetic pulse directed counter to the magnetic pulse and the counteroscillator is moved by the magnetic pulse along a translation axis such that the pulse of the impact acting on the tool is at least partially compensated ,
• the magnetic pulse generates an eddy current in a percussion eddy current receiver operatively connected to the tool, a counter-magnetic pulse directed counter to the magnetic pulse being generated as a function of the eddy current and the percussion eddy current receiver being moved along the striking axis as a function of the magnetic pulse and produces such a blow, and the blow is delivered at least indirectly to a tool.
• the Schlagtechnik eddy current receiver is preferably connected to a firing pin, wherein the impact of the firing pin can be transferred to the tool.
• an ordinary tool can advantageously be operatively connected to the eddy-current generator via the firing pin.
• the counteroscillator and the percussion eddy current receiver driving the tool are driven by the same eddy current generator. At least part of the impact energy of the method is preferred in the method
• Figure 1 shows an embodiment of a hammer mechanism 1 for a hand tool.
• the hand tool can be, for example, a percussion hammer or electric chisel.
• the striking mechanism 1 has a receiving device 14 for a tool 12.
• the tool 12 is formed in this embodiment as a chisel.
• the receiving device 14 is designed to guide the chisel 12 such that the chisel 12 can be moved back and forth along a striking axis 30.
• the receiving device 14 is formed, for example, a hollow cylindrical shape, and encloses a cylindrical lumen, in which the tool, in particular bit, at least partially can be performed.
• the striking mechanism 1 also has an eddy current drive.
• the eddy current drive has an electrical coil with coil windings, of which the coil windings 24 and 26 are designated by way of example.
• the coil is designed as a flat coil, which in this embodiment coil turns of an electrically particularly good conductive material, such as copper.
• the coil turns of the coil have a rectangular cross section in this exemplary embodiment.
• the coil is formed in this embodiment as a flat coil, which is connected to a bobbin 22.
• the bobbin 22 is formed for example of bonded with epoxy resin glass fibers or of a ceramic material.
• the flat coil and the coil support 22 each extend in a plane which runs perpendicular to the striking axis 30.
• the coil with coil windings 24 and 26 is designed to generate current flowing through a magnetic pulse, which can generate an eddy current in the effective range of the coil in an eddy current receiver 36.
• the eddy current receiver 36 is formed as a good electrically conductive plate, for example made of copper material, which is connected in this embodiment with the tool, in particular the chisel 12.
• the tool, in particular the chisel 12 can be formed in this embodiment of a hard, less well e- lektrisch conductive material, such as steel.
• the eddy current generated in the eddy current receiver 36 generates its own counter-magnetic pulse, which cooperates with the magnetic pulse generated by the coil, wherein the magnetic pulse of the coil and the counter-magnetic pulse generated by the eddy current repel each other.
• a shock wave is generated, which as along the striking axis 30 in the chisel 12 propagating shock wave 34, in particular longitudinal wave, moved from the eddy current receiver to a chisel tip.
• a cover plate 19 which has an opening in the region of the coil, so that magnetic field lines which have been generated by the coil through which breakthrough can reach the Schlagtechnik- eddy current receiver.
• the cover plate 19 is formed for example of steel and protrudes with a projecting portion transverse to the impact axis 30 radially inwardly, so that the tool 12, in particular the chisel, against the coil can strike against the cover plate 19 when moving back against the coil and thus is stopped against further movement ,
• an acceleration sensor in particular a disk-shaped piezoelectric element 18, is arranged along the striking axis 30.
• the disk-shaped piezoelectric element 18 has an opening through which magnetic field lines of the magnetic pulse generated by the coil can pass.
• the piezoelectric element 18 is designed to generate an acceleration signal as a function of a pressure exerted by the tool 12 on the cover plate 19 on the piezoelectric element 18 and output this on the output side.
• the hand tool can, for example, in response to the acceleration signal energize the coil for emitting a magnetic pulse.
• the acceleration signal energizes the coil for emitting a magnetic pulse.
• a strike of the striking tool can be triggered.
• a backward movement of the tool and / or a shock wave reflected at a tool end can be detected, and in dependence the acceleration signal - for example, controlled by a control unit - triggering a further blow done.
• the hammer mechanism 1 also has a counteroscillator 39, which is connected to an eddy current receiver 35.
• the eddy current receiver 35 is in this embodiment of a particular good electrically conductive
• the striking mechanism 1 also has a counteroscillator receptacle 15, which is connected to the coil carrier 22.
• the counter-oscillator receptacle 15 is designed to guide the counter-oscillator 39 along the striking axis 30 in a lumen 31.
• the lumen 31 is connected to a tube 42 in the region of one end of the counteroscillator receptacle 15, wherein the tube 42 encloses a lumen 33 and connects the lumen 31 with the lumen enclosed by the tool receptacle 14 in the region of the coil carrier 22.
• the lumen enclosed by the tool receptacle 14 is thus connected to the lumen 31 of the counter-oscillator receptacle 15 via the lumen 33 of the tube 42.
• the counter-oscillator receptacle 15 has in the region of the end a spring, in particular a plate spring 44.
• the spring 44 is designed to be compressed by the counter-oscillator 39 moving along the striking axis 30 in the direction of the spring 44 and to push back again in the direction of the striking axis.
• the counter-oscillator 39 compresses the air volume 31, the air volume of 33 in the tube 42 is also compressed.
• the tool 12 can thus compress the air volume 33 together with the air volume 31 during a return movement in the direction of the coil carrier 22 along the striking axis 30 and move the counter-oscillator 39 back into the starting position.
• the air volume 31 and the air volume 33 may together with the counteroscillator 39 form a spring-mass system whose resonant frequency corresponds to a beating frequency of the hand tool.
• a backward movement of the particular ferromagnetically shaped counter-oscillator 39 can be effected or assisted by means of a magnetic pulse generated by the coil with the coil turns 24 and 26, so that the counter-oscillator 39 is attracted by the coil and back to an initial position can be moved back.
• FIG. 2 shows an exemplary embodiment of a hammer mechanism 10 of a craft tool.
• the hammer mechanism 10 like the striking mechanism 1 in FIG. 1, has the same grain size. on components, which are each provided with the same reference numerals. The same components have the same functions as the components shown in Figure 1, each having the same reference numerals.
• the percussion mechanism 10 may be connected to the counter-oscillator 39 and the counter-oscillator receiver 15, or additionally to the tube 42, instead of the percussion mechanism 1. An impulse of the tool 13 or additionally of the firing pin 25 can then be at least partially compensated by the counteroscillator 39.
• the percussion mechanism 10 in FIG. 2 has a chisel as a tool 13 of the percussion mechanism 10.
• the tool 13 is - unlike the tool 12 in Figure 1 - not formed for generating an eddy current.
• the impact mechanism 10 has - unlike in Figure 1 - a firing pin 25, which along the impact axis 30 between the tool 13 and the eddy current generator, comprising the bobbin 22 and the coil, is arranged.
• the firing pin 25 is formed in this embodiment, to generate an eddy current in response to the magnetic pulse generated by the coil.
• the firing pin 25 has a plate 37 consisting of electrically preferably highly conductive material, which is arranged facing the coil along the striking axis 30.
• the plate 37 is connected to the firing pin 25 and forms part of the firing pin 25, which may be formed, for example, except for the eddy current receiver made of steel.
• the firing pin 25 is received by the tool holder 14 and arranged movably in the tool holder 14.
• the tool holder 14 has - in contrast to the tool holder 14 in Figure 1 - in addition to a sensor coil 16.
• Sensor coil 16 is annular and encloses a lumen in which the tool 13 is arranged at least partially back and forth.
• the sensor coil 16 is designed to detect a movement of the tool 13 along the striking axis 30 - that is, through the sensor coil 16 - and to generate a sensor signal by means of electromagnetic induction and output this on the output side.
• the sensor coil 16 may, for example, be connected to a control unit, wherein the control unit is designed to energize the coil for generating a shock as a function of the sensor signal. This can be done, for example, so efficiently that the coil 30 is first energized to generate a shock when the tool 13 is fully energized. has constantly moved along the striking axis 30 in the direction of the coil against the firing pin 25 and is ready for further forward movement.
• the control unit by means of the coil 52 of the eddy current generator - formed from the coil with the coil windings 24 and 26 and the bobbin 22 - detect a time course of the eddy current formation in the Schlagtechnik eddy current receiver, generating an eddy current representing eddy current signal and generate a further magnetic pulse - for example, as part of a temporal sequence of magnetic pulses - in response to the eddy current signal.
• FIG. 3 shows an exemplary embodiment of a striking mechanism 20 of a hand tool.
• the percussion mechanism 20 has an eddy-current generator with a coil carrier 22, on which a flat coil is arranged, of whose coil turns the coil turns 28 and 29 are designated by way of example.
• the flat coil is designed in such a way that coil windings located radially further outward have a dimension extending in the direction of the striking axis 30, which dimension is larger than coil turns located radially further inwards.
• the coil can thus advantageously form a helical shape, which is shown in more detail in Figure 4.
• the helical shape thus formed by means of the coil causes the tool 1 1 of the percussion mechanism 20 can be set in a rotational movement 32, which is superimposed on the translation movement along the striking axis 30 caused by the shock wave 34.
• the tool 1 1 can thus simultaneously exert a drilling rotational movement during a beating operation.
• the percussion mechanism 20 may be connected instead of the percussion mechanism 1 with the counteroscillator 39 and the counter-oscillator holder 15, or additionally with the tube 42. A pulse of the tool 1 1 can then be at least partially compensated by the counteroscillator 39.
• FIG. 4 shows an exemplary embodiment of an outer coil turn 29 of the flat coil already shown in FIG.
• the coil turn 29 extends along a circumferential direction increasingly in the direction of the striking axis 30, so that the coil turn along the striking axis 30 forms a helical shape.
• the helical shape causes the tool 1 1 can perform a rotational movement 32 when energizing the coil.
• Figure 5 shows a circuit arrangement for a percussion of a hand tool, which is designed to generate an eddy current, which can put a tool in a striking motion.
• circuit arrangement 50 has a voltage source 60 which, for example, has a high voltage of several kilovolts, preferably at least 7 kilovolts or at least 10 kilovolts.
• the voltage source 60 is connected via a resistor 62 to an anode terminal of a thyristor 58.
• the thyristor 58 has a cathode terminal, which is connected to the other terminal of the voltage source 60.
• the thyristor 58 has a control connection, which is connected via a connecting line 66 to a control unit 56.
• the control unit 56 is connected on the input side via a connecting line 65 to a sensor coil 16.
• the control unit 56 is also connected on the input side via a connecting line 64 to the acceleration sensor 18, which has been shown in FIG. 1 and in FIG. 2 and has already
• the anode terminal of the thyristor 58 is connected to a first terminal of a capacitor 54.
• the capacitor 54 has a second terminal which is connected to a first terminal of a coil 52.
• the coil 52 is part of an eddy-current generator already shown in FIGS. 1 and 2, which is designed to generate a magnetic pulse through current.
• the coil 52 has a second terminal which is connected to the cathode terminal of the thyristor 58 and also to the voltage source 60.
• the hand tool for example the hand tool shown in FIG. 2
• the tool presses against the firing pin and causes the acceleration sensor to generate an acceleration signal by a pressure exerted thereon in particular a voltage.
• the acceleration sensor 18 may send the acceleration signal to the control unit 56 via the connection line 64.
• the control unit 56 is designed to generate a trigger signal as a function of the acceleration signal and output this via the connecting line 66 and thus to ignite the thyristor 58.
• the control unit 56 is connected via a connecting line 67 with the coil 52 and may, in addition to or independent of the acceleration sensor 18, generate the trigger signal in response to a waveform of a voltage induced in the coil 52 by the eddy current.
• a stroke of the tool 12 or 13 is for example between three and four millimeters.
• the capacitor 54 which was previously charged by the voltage source 60 via the resistor 62 with electrical charge, can thus discharge its charge via the thyristor 58, and via the capacitor 52 connected in series with the coil.
• the discharge current of the capacitor 54 - preferably the capacitor 54 and the coil 52 is in resonance - is converted in the coil 52 into a magnetic pulse.
• the magnetic pulse can be generated by the striking mechanism shown in FIG.
• Eddy current receiver 36 are received by the Schlagtechnik- eddy current receiver 37 shown in Figure 2 or from the eddy current receiver 35 shown in Figure 1 counter-oscillator 39 and each generate an eddy current, which can each generate a counter-magnetic pulse, so that the firing pin 25 or the percussion eddy current receiver
• a renewed generation of a trigger signal by the control unit 56 can be effected in dependence on an acceleration signal, a sensor signal of the sensor coil 16 or a signal curve of a voltage induced by the eddy current in the coil 52.
• the control unit 56 is designed to attract the particular ferromagnetically formed counteroscillator 39 by means of a magnetic pulse, in particular a DC magnetic pulse and to move it back to an initial position.
• the thyristor can be ignited by the control unit 56.
• the resistor 62 has a resistance value such that during the firing of the thyristor 58, the capacitor 54 can be discharged via the coil 52, wherein the voltage source 60 is not short-circuited.
• FIG. 6 shows an embodiment of an operation of the impact mechanism already shown in Figures 1, 2 and 3.
• FIG. 6 shows an arrangement 70 which has a coil 76 as part of an eddy-current generator, one with the coil 76 connected AC voltage source 80, and a flat, electrically particularly good conductive eddy current receiver 74, which is connected to a along a striking axis 30 longitudinally extending tool 72.
• the alternating voltage source 80 can generate a current which flows through the coil 76 in a current direction during a half cycle of the alternating voltage-indicated in FIG. 6 by means of the arrows on the coil 76 -and thus generates a magnetic pulse 77.
• the magnetic pulse 77 causes in the eddy current receiver 74 an eddy current 85, which generates a magnetic pulse 78 opposite the magnetic pulse 77.
• Figure 7 shows schematically an embodiment of a percussion 90 with
• the hammer mechanism 90 has a ferromagnetic cup 92, the cup being magnetically conductively connected to a ferromagnetic core 94 in the region of a cup bottom of the cup 92, so that a magnetic flux can flow from the core into a cup wall.
• the core 94 is cylindrical in this embodiment and extends from the cup bottom to a cup rim, so that between an outer cylinder wall of the core and a cup inner wall a - transverse to a striking axis 30 - annular air gap is formed.
• the inner wall of the cup is formed, for example, in the shape of a cone, so that a volume forming the air gap has a conical section with an outer conical surface and a cylindrical inner casing surrounding the core 94.
• a hollow cylindrical, in this embodiment, cup-shaped ferromagnetically formed armature 100 is arranged to be movable back and forth as an eddy current receiver, wherein a cup wall
• the armature 100 is immersed in the air gap 96.
• the armature has in the region of one end a striking nose 102, which is designed to deliver a shock to a tool 13 when the armature 100 is moved along the striking axis 30.
• the core is surrounded by an electric cylindrical coil whose magnetic field lines in the energized state run inside the coil 98 along or parallel to the striking axis 30 in the core 94.
• the coil 98 is connected to a current source 106, which is designed to generate an AC pulse for generating a magnetic pulse for expelling the armature 100 and thus to generate an eddy current in the armature 100, in particular in the cup wall 101, whereby the armature from the air gap along the striking axis 30 is moved out and can deliver a blow to the tool 13 with the blow nose 102.
• the tool 13 is held in a tool holder 14 in particular back and forth.
• the percussion mechanism can have, in addition to the coil 98, a flat coil 104 arranged on one end side of the core 94, which is connected in series with the coil 98, for example, or is connected to the coil 98 in parallel with the current source 106.
• the pancake 104 may generate an additional eddy current in a cup bottom of the armature 100, which enhances the impact energy of the armature.
• the conical shape of the air gap causes an increasing magnetic field strength of the magnetic field generated by the coil 98 in the air gap 96 starting from the cup bottom to the cup edge of the cup 92, so that the armature 100 with increasing exit from the air gap 96 a constant or increasing the cup wall 101 acting Austriebskraft experiences.
• FIG. 8 shows the percussion mechanism 90 shown in FIG. 7, in which the armature has partially moved out of the air gap 96 along the striking axis 30 and strikes against the tool 13.
• the armature is shown in Figure 8 in a position 100 '.
• the current source 106 is designed to generate a DC pulse after the AC pulse or after a pulse pause to drive off the armature and to withdraw the armature into the air gap 97 by means of the DC pulse. By periodically generating a total pulse or a pair of pulses comprising an AC pulse and a DC pulse, periodic beats can be generated periodically.
• the percussion mechanism 90 can be connected to a counter-oscillator driven by eddy current.
• FIG. 9 shows a diagram with a time axis 1 10 and an amplitude axis 1 12, in which an exemplary embodiment for a previously described overall pulse 1 13 comprising an alternating-current pulse 1 14 and a direct-current pulse following the alternating-current pulse 1 14.
• the AC pulse 1 14 has an AC pulse duration 1 16 and the DC pulse 1 15 has a DC pulse duration 1 18 on.
• the ratio of the AC pulse duration 1 16 to the DC pulse duration 1 18 is for example 3: 1, so that the AC pulse duration 1 16 of the AC pulse 1 14 three quarters of a total pulse duration of a total pulse 1 13 for generating a shock, and the DC pulse duration 1 18 of the DC pulse 1 15th a quarter of the total pulse duration is.
• a beat frequency may be, for example, 50 hertz.
• the total pulse duration is for example 20 milliseconds, the AC pulse duration 1 16 is then 15 milliseconds and the DC pulse duration 1 18 five milliseconds.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Percussive Tools And Related Accessories (AREA)
• Food-Manufacturing Devices (AREA)

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• 2010
  • 2010-11-05 DE DE102010043447A patent/DE102010043447A1/de not_active Withdrawn
  • 2010-11-30 WO PCT/EP2010/068450 patent/WO2011082892A1/de active Application Filing
  • 2010-11-30 EP EP10787371A patent/EP2512747A1/de not_active Withdrawn
  • 2010-11-30 CN CN2010800570382A patent/CN102655987A/zh active Pending

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