WO2018099743A1

WO2018099743A1 - Sharpening device

Info

Publication number: WO2018099743A1
Application number: PCT/EP2017/079706
Authority: WO
Inventors: Peter Heywood; Tilmann Behr
Original assignee: Robert Bosch Gmbh
Priority date: 2016-11-29
Filing date: 2017-11-20
Publication date: 2018-06-07
Also published as: DE102016223677A1; CN110023019B; CN110023019A

Abstract

The invention relates to a sharpening device for portable machine tools, in particular for chain saws, having at least one grinding unit (14a; 14b), which, for sharpening at least one cutting element (16a) of a cutting strand (18a), in particular a saw chain, of the portable machine tool, has at least one movably mounted grinding element (20a; 20b), having at least one actuating unit (22a; 22b) for moving the at least one grinding element (20a; 20b) relative to the cutting strand (18a), and having at least one limiting unit (24a; 24b) at least for limiting a sharpening force that can be exerted on the at least one cutting element (16a) by means of the at least one grinding element (20a; 20b) during a sharpening operation. According to the invention, the at least one limiting unit (24a; 24b), in particular in addition to limiting the sharpening force, be provided to limit a duration of an action of the sharpening force that can be exerted on the at least one cutting element (16) by means of the at least one grinding element (20a; 20b).

Description

description

sharpener

State of the art

A sharpening device for portable machine tools, in particular for chainsaws, is already known from WO 2014/098682 A1, wherein the sharpening device has at least one grinding unit which has at least one movably mounted grinding element for sharpening at least one cutting element of a cutting strand, in particular a saw chain, of the portable machine tool , at least one actuating unit for a movement of the at least one grinding element relative to the cutting strand, and at least one limiting unit comprises at least a limitation of a sharpening force which can be exerted on the at least one cutting element during a sharpening operation by means of the at least one grinding element.

Disclosure of the invention

The invention relates to a sharpening device for portable machine tools, in particular for chainsaws, with at least one grinding unit, which at least one cutting element of a cutting strand, in particular a saw chain, the portable power tool has at least one movably mounted grinding element with at least one operating unit to a Movement of the at least one grinding element relative to

Cutting strand, and with at least one limiting unit at least to a limit of a practicing during a sharpening operation by means of the at least one grinding element on the at least one cutting element exercisable sharpness. It is proposed that the at least one delimiting unit, in particular in addition to the limitation of the sharpening force, is intended to limit a duration of an action of the sharpening force which can be exerted on the at least one cutting element by means of the at least one grinding element. The term "provided" should be understood to mean in particular specially designed and / or specially equipped, in particular that an object is intended for a specific function should be understood to mean that the object fulfills this specific function in at least one application and / or operating state The duration of an action of the sharpening force is preferably a period of time during which the grinding element and the cutting strand are in contact and in particular a sharpening force is exerted on the cutting element by the grinding element The sharpening force is preferably a force with in that the grinding element can be pressed against the cutting strand, in particular pressed, and / or which can be exerted by the cutting element in at least one sharpening process from the grinding element onto the cutting element.

Preferably, the grinding element can be pressed against the at least one cutting element along a direction extending at least substantially parallel to a cutting plane of the cutting strand. A movement axis of the grinding element preferably runs at least substantially perpendicular to the cutting plane of the cutting strand. In particular, the cutting element can be sanded, in particular sharpened, by means of a sharpening force acting on the cutting element by the grinding element in a manner already known to a person skilled in the art. A sharpening of a cutting element of a cutting strand by the action of a sharpening force is disclosed, for example, in WO 2014/098682 A1.

The grinding element is preferably at least partially abrasive. The abrasive element may comprise, for example, quartz, corundum, emery, pumice, garnet, natural diamonds, synthetic corundum (Al 2 O 3), silicon carbide (SiC), cubic boron nitride (cBN), synthetically produced diamond or the like. However, it is also conceivable that the grinding element comprises another material that appears meaningful to a person skilled in the art, which material can be used to enable a sharpening process. The sharpening force, which can be exerted on the cutting element by means of the grinding element to enable a sharpening process, can be achieved by means of an electrically actuatable actuator, by means of a mechanical actuator Force transducer, which can be actuated in particular by an operator by means of the actuating unit, by means of an interaction of one of the aforementioned possibilities or to another, a person skilled in the sense appearing manner generated. The mechanical force transducer can be designed, for example, as a lever mechanism, as a gear transmission, as a combination of a lever mechanism and a gear transmission or the like. The grinding element is preferably provided to sharpen, in particular sharpen, a plurality of cutting elements of the cutting strand, in particular all grinding elements of the cutting strand, during a sharpening operation, in particular during a movement of the cutting strand relative to the grinding element, in particular as a result of driving the cutting strand by means of a Drive unit and / or a transmission unit of the portable power tool. The grinding unit is particularly preferably intended to provide the at least one cutting element, in particular a plurality of cutting elements of the

Schneidstrangs, arranged in a on the portable machine tool

Sharpen the state of the cutting strand.

The cutting strand is particularly preferably designed as an endless cutting strand, in particular as a saw chain, which can be driven circumferentially and / or oscillating along a circumference of a guide unit, in particular a guide blade, of the portable machine tool. The cutting strand designed as a saw chain is preferably designed as a saw chain to be sharpened from an upper side, in particular as a so-called top sharpening chain. The guide unit is preferably designed as a guide blade, on which the

Cutting strand can be arranged and by means of which the cutting strand is feasible. The

Guide unit is preferably provided to exert a constraining force at least along a direction perpendicular to a cutting direction of the cutting strand direction on the cutting strand to specify a possibility of movement of the cutting strand along the cutting direction. Preferably, the guide unit has at least one guide element, in particular a guide groove cooperating with the cutting strand, or one with the guide groove

Cutting strand co-operating guide web, through which the cutting strand is guided. Preferably, the cutting strand, in the cutting plane of the

Viewed along a major part of an entire circumference of the guide unit by the guide unit by means of the guide element leads. Preferably, the cutting plane is aligned in a processing of a workpiece transversely to a machined workpiece surface. However, it is also conceivable that the cutting plane is aligned during machining of a workpiece at least substantially parallel to a machined workpiece surface. In this case, the term "cutting plane" should in particular define a plane in which the cutting strand is moved circumferentially around the guide unit along at least one operating state along a circumference of the guide unit. "At least substantially parallel" is intended here in particular to align a direction relative to a reference direction , in particular in a plane, are understood, wherein the direction relative to the reference direction has a deviation, in particular less than 8 °, advantageously less than 5 ° and particularly advantageously less than 2 °. In addition, "orientation at least substantially perpendicularly" should in particular define an orientation of a direction relative to a reference direction, the direction and the reference direction, in particular in one plane, including an angle of 90 ° and the angle a maximum deviation of, in particular, smaller than 8 °, advantageously smaller than 5 ° and particularly advantageously smaller than 2 °. A "cutting direction" is to be understood in particular as a direction along which the cutting strand is used to produce a cutting gap and / or for separating and / or abrading Material particles of a to be processed

Workpiece in at least one operating state due to a driving force and / or a drive torque, in particular on the guide unit is moved. Preferably, the cutting strand is moved in an operating state along the cutting direction relative to the guide unit in the guide groove or on the guide web of the guide unit.

The actuating unit is preferably connected to the limiting unit, in particular connected in terms of motion technology. The limiting unit preferably comprises at least one, in particular movably mounted, movement transmission element and / or at least one fluid damper element, wherein the motion transmission element and / or the fluid damper element is connected to a, in particular movably mounted, actuating element of the actuating unit, in particular fixed thereto or in one piece is formed with this. Preferably, a movement of the actuating element is transferable to the movement transmission element and / or to the fluid damper element, in particular to a movement of the grinding element relative to the cutting strand by means of the actuating unit via the limiting unit, preferably to bring the grinding element with the cutting strand in contact. An at least partially integral formation of the limiting unit and the actuating unit is also conceivable. The fact that a unit is formed at least partially in one piece with another unit, is to be understood in particular that the unit and the further unit have a common component which is intended to fulfill a function of the unit and the further unit. By means of the embodiment of the sharpening device according to the invention, a constant result of a sharpening operation can advantageously be achieved, which is preferably independent of a variation of an action of an operator force. It can advantageously a long life of the cutting strand, in particular the saw chain, and thus the portable machine tool are made possible. It may be advantageous to premature failure of the cutting strand, in particular the saw chain, as a result of a faulty sharpening by too long a duration

Action of a sharpness counteracted. In addition, advantageously due to a limitation of the sharpening force and the duration of an action of the sharpening force, in particular a sharpening period, a local overheating can be avoided by a high force on the cutting element. Advantageously, a loss of hardness of the cutting element can be avoided. A particularly optimal duration of an action of the sharpening force, in particular a sharpening period, can be realized, which is tailored to the cutting strand and / or the grinding element, in particular to a material of the

Cutting strand and / or the grinding element is tuned.

Furthermore, it is proposed that the limiting unit comprises at least one mechanical force transducer and / or electronics for limiting the sharpening force and the duration of an action of the sharpening force. The limiting unit may be at least partially designed as an electronic limiting unit and / or at least partially as a mechanical limiting unit. It is also conceivable that the limiting unit, in particular in at least one embodiment of the sharpening device according to the invention, is designed as a purely mechanical limiting unit. In one embodiment of the limiting unit as at least partially electronic limiting unit, it is conceivable that the sharpening force by means of a sensor element, in particular by means of a force sensor, the limiting unit and / or the duration of an action of the sharpening force by means of a particular electronic timer of the limiting unit monitors and / or detected is, for example, based on signals of the sensor element and / or the timer, a control of at least one actuator the limiting unit moves, which moves the grinding element relative to the cutting element. Preferably, the electronics of the delimiting unit, in particular in the case of an at least partial electronic embodiment of the delimiting unit, comprise at least one electronic control unit which includes at least one processor unit and at least one memory unit and at least one operating program stored in the memory unit

Having control of at least one actuator of the limiting unit. The electronics of the limiting unit preferably comprise, in particular in the case of an at least partial electronic configuration of the limiting unit, at least one sensor element for detecting a force characteristic of the grinding element and / or a timer for monitoring and / or controlling a timer

Duration of an effect of the sharpness. The electronics of the limiting unit preferably comprises, in particular in the case of an at least partial electronic design of the limiting unit, at least one sensor element for detecting a force characteristic of an actuator, such as an electronically controllable power cylinder or the like, and / or a timer for monitoring and / or control a duration of an action of the sharpness. The electronics of the delimiting unit can preferably be supplied with energy by means of the portable power tool, in particular by means of a battery pack of the portable power tool and / or by means of a power cord of the portable power tool. The limiting unit preferably comprises at least one mechanical force transducer, in particular in one embodiment of the limiting unit as at least partially or as a purely mechanical limiting unit. The limiting unit preferably comprises at least one mechanical force transducer and at least one damping unit at least for damping an operator force that can be exerted on the actuating unit by an operator, in particular in an embodiment of the limiting unit as at least partially or as a purely mechanical limiting unit. Further embodiments of the delimiting unit appearing expedient to a person skilled in the art in the case of an at least partially electronic and / or at least partially mechanical design of the delimiting unit also conceivable. By means of the embodiment according to the invention can advantageously be realized cost-effectively and structurally simple a limitation of the sharpening force and the duration of an action of the sharpening force, in particular a sharpening period. It can be advantageously achieved a constant result of a sharpening operation, which is preferably independent of a variation of an action of an operator. It can be a particularly optimal duration of exposure to a sharpness, in particular a sharpening time, realized that is tailored to the cutting strand, in particular is tuned to a material of the cutting strand.

Furthermore, it is proposed that the limiting unit is designed such that the sharpening force and the duration of an action of the sharpening force have an at least substantially reciprocal proportionality to each other. Preferably, the limiting unit is designed such that a product, in particular a sharpening power or a sharpening effect of the grinding unit, from the

Sharpening force and the duration of an action of the sharpening force is at least substantially constant. Preferably, the limiting unit is designed such that at a high sharpening force a short duration of action of the sharpening force is adjustable or that at a low sharpening a long duration of action of the sharpening force is adjustable. Preferably, the at least essentially reciprocal proportionality of the sharpening force and the duration of an action of the sharpening force as a result of the at least partial mechanical and / or the at least partial electronic configuration of the limiting unit can be realized. By means of the embodiment according to the invention, a constant product of the sharpening force and the duration of an action of the sharpening force, in particular a sharpening period, of the sharpening operation can be advantageously achieved, which is independent of a continuous actuation of the actuating unit by an operator. By means of the inventive design of the sharpening device can advantageously at least a largely constant product, in particular a sharpening power or a sharpness effect of

Abrasive unit, from the sharpness and the duration of an action of the sharpening force can be achieved.

In addition, it is proposed that the limiting unit has at least one fluid-damping element at least for damping by an operator of having the actuator on the limiting unit exercisable operator force. The fluid damper element can be designed as a gas damper element, in particular as an air damper element, as a hydraulic damper element, in particular as an oil pressure damper element, or the like. Preferably, the actuation unit comprises at least the movably mounted actuating element, on which the fluid damper element is arranged. The actuating element can be designed as a translationally movably mounted pushbutton, as an actuating lever, as an actuating slide or the like. It is also conceivable that the actuating element is formed integrally with a component of the fluid damper element, in particular in a configuration of the actuating element as a translationally movably mounted push button. By "one-piece" should be understood in particular to be at least materially bonded, for example by a welding process, an adhesive process, an injection molding process and / or another process that appears expedient to a person skilled in the art, and / or advantageously shaped in one piece, for example by a

Manufacture from a casting and / or by a production in a one- or multi-component injection molding process and advantageously from a single blank. Preferably, the actuating element is connected by means of the fluid damper element in terms of movement with the grinding element. If, for example, the actuating element is actuated by an operator, in particular an operator force is exerted via the fluid damper element at least partially on the movement transmission element, in particular a lever element on which the grinding element is arranged. By means of the embodiment according to the invention can advantageously be achieved a constant result of a sharpening operation, which is preferably independent of a variation of an action of an operator. It can advantageously a long life of the cutting strand, in particular the saw chain, and thus the portable machine tool are made possible. Furthermore, it is proposed that the limiting unit comprises at least two relatively rotatable and / or rotatable motion transmission elements, in particular levers, which are movable by means of at least one fluid damper element of the limiting unit, wherein the grinding element is arranged on at least one of the motion transmission elements. At least one of the motion transmission elements can be used as a lever, as Gear, as a lever with at least one toothed portion o. The like. Be formed. In one embodiment of the at least two motion transmission elements as levers, the motion transmission elements have a common pivot axis. In an embodiment of the motion transmission elements, the motion transmission elements preferably extend in a direction away from the common pivot axis to a large part of a maximum longitudinal extension of the respective movement transmission element, in particular opposite directions. In particular, at least more than 50%, preferably at least more than 75% and particularly preferably at least more than 90% of a reference value should be understood as meaning a "majority." In one embodiment of the motion transmission elements as levers, the fluid damper element is preferably one end with one of the motion transmission elements In one embodiment of the motion transmission elements as levers, the motion transmission elements are preferably interconnected in terms of motion by means of the fluid damper element A movement of at least one of the as Lever formed motion transmission elements is preferably transferable by means of the fluid damper element on the further motion transmission element of the motion transmission elements In an embodiment of at least one of the motion transmission elements as a lever with at least one toothed section and a configuration of the further motion transmission element as a toothed wheel, the motion transmission elements have mutually offset motion axes. The motion transmission element designed as a lever with at least one toothed section preferably has a pivot axis which is arranged offset parallel to a rotation axis of the further motion transmission element designed as a gear. By means of the embodiment according to the invention, an at least almost linear relationship between force and time can advantageously be achieved, whereby a constant result of a sharpening process can be achieved, which is preferably independent of a variation of an action of an operator force. It is also proposed that the limiting unit has at least one restoring spring element for resetting the grinding element into an initial position and at least one fluid damper element for damping at least one operator force that can be exerted on the limiting unit by an operator from the actuating unit, wherein a maximum spring force of the

Return spring element is greater than a maximum fluid damper force to an independent of the operator force of an operator extending movement of a piston rod of the fluid damper element. The return spring element is preferably designed as a compression spring, in particular as a helical compression spring. However, it is also conceivable that the return spring element another, a

As a tension spring, in particular as a coil spring, as a torsion spring, as a leaf spring, leg spring o. The like. Preferably, the return spring element with one end on one of the Bewegungsübertragungselemen- te, in particular on the motion transmission element to the grinding element is arranged, arranged, in particular fixed. Preferably, the restoring spring element is supported by the end on one of the movement transmission elements, in particular on the motion transmission element on which the grinding element is arranged. With another end, the restoring spring element is preferably arranged, in particular fixed, on the portable machine tool, in particular on a housing, on the guide unit or the like. Preferably, the restoring spring element is supported by the other end on the portable machine tool, in particular on a housing, on the guide unit or the like. The fluid damper element is preferably arranged between the actuating element of the actuating unit and one of the movement transmission elements of the limiting unit. Preferably, the piston rod of the fluid damper element is arranged on one of the motion transmission elements, in particular fixed thereto. By means of the embodiment according to the invention, a reliable resetting of the sharpening device into an initial state can advantageously be achieved. Advantageously, a retraction movement of the piston rod of the fluid damper element into a fluid damper housing of the fluid damper element can be achieved by means of the return spring element upon impact of the fluid damper element, in particular to realize a structurally simple limitation of the sharpening force and the duration of an action of the sharpening force. In addition, it is proposed that the limiting unit has at least one retaining element which is provided to hold at least one movement transmission element of the limiting unit and / or an actuating element of the actuating unit in an unactuated position if there is no exceeding of an actuating force limit value. The holding element is preferably movably mounted. Preferably, the retaining element is movably mounted against a spring force of a retaining spring of the limiting unit. However, it is also conceivable that the holding element itself is resilient. Preferably, the holding element cooperates to hold the movement-transmitting element and / or the actuating element with a holding extension of the motion-transmitting element and / or of the actuating element. When an operating force limit value is exceeded, decoupling of the holding element and of the movement transmission element and / or of the actuating element, in particular of the holding extension, is preferably effected in order to enable or enable a movement of the motion transmission element and / or of the actuating element. However, it is also conceivable that the actuating force limit value can be monitored by means of a sensor element and the holding element in response to a sensor signal of the sensor element is controlled by the electronics, in particular to enable or enable movement of the motion transmitting element and / or the actuating element. Other embodiments of the retaining element which appear appropriate to a person skilled in the art are likewise conceivable. By means of the embodiment according to the invention can be advantageously ensured that a minimum actuation force on the actuator and / or the limiting unit is exerted by an operator before a movement of the grinding element takes place, in particular to ensure that the grinding element even with a slow movement of the motion transmission element and a slowly compressing the fluid damper element, the grinding element is reliably pressed against the cutting element.

Furthermore, it is proposed that the sharpening device has at least one stop variation unit for changing a position of a mechanical stop element of the delimiting unit as a function of wear of the at least one grinding element and / or the at least one cutting element. includes elements. Preferably, the stop variation unit comprises at least one resilient detent element, which cooperates with the stop element, in particular is fixed to the stop element. The latching element preferably engages in at least one latching recess of the Anschlagvariationseinheit to fix the stopper element in one position. The latching element is preferably designed as a leaf spring. In the case of a decrease in a material thickness of the grinding element as a result of wear, in particular a maximum compression distance of the return spring element changes, so that a spring force of the return spring element acting on the stop element changes, in particular increases, as a function of wear of the grinding element. Preferably, the latching element is movable into a further latching recess of the Anschlagvariationseinheit to change a position of the stop element, in particular in dependence on wear of the grinding element. By means of the embodiment according to the invention can advantageously a largely constant sharpening power over a lifetime of the

Sharpening device can be achieved. It can be advantageously achieved an automatic compensation of a position of the stop element due to wear of the grinding element. It can be advantageously compensated for as a result of wear of the grinding element increasing distance of the grinding element relative to the stop element and the cutting strand. It can be advantageously ensured that a reliable sharpening process can be carried out.

It is also proposed that the sharpening device comprises at least one dispensing unit which outputs a wear information to an operator as a function of a position of the mechanical stop element. A position of the stop element can be electronically and / or mechanically monitored and used to influence a state of an output element, such as a colored slider, a display, an LED o. The like., To influence. The sharpening device preferably comprises at least one output unit for outputting a state of wear of the at least one grinding element and / or the at least one cutting element which comprises the output element. The output unit can be designed as a haptic, as an acoustic and / or as an optical output unit. By means of the embodiment according to the invention, advantageously a reliable grinding process can be realized. It may be advantageous for an operator to determine a state of the grinding element ment and / or the cutting strand are issued, in particular before a failure of the grinding element and / or the cutting strand.

In addition, a portable machine tool, in particular a chain saw, proposed with a sharpening device according to the invention. Under one

In this case, a "portable power tool" is to be understood here as meaning, in particular, a machine tool for machining workpieces, which can be transported by a servant in a transport machine-free manner 10 kg and more preferably less than 5 kg.Especially portable machine tool is designed as a chainsaw.The portable machine tool can be designed as a battery-chain saw or a wired chainsaw., It is also conceivable that the portable power tool another, a The wearable machine tool may be battery-powered or wired particular on a sword tip of the guide blade, the portable power tool, be arranged on a detachably attachable to the guide unit Schneidstrangschutzhülle the portable power tool or other, a professional appear appropriate sense position of the portable power tool. The sharpening device can be embodied as part of the portable machine tool or the sharpening device can be designed as a retrofit kit, which can be detachably attached to the portable machine tool, in particular to the housing or to the guide unit, and which can be retrofitted to the portable machine tool by an operator the portable power tool can be arranged. By means of the embodiment according to the invention can advantageously be achieved a constant result of a sharpening operation, which is preferably independent of a variation of an action of an operator. It can advantageously a long life of the cutting strand, in particular the saw chain, and thus the portable machine tool are made possible. It can advantageously be a premature failure of the cutting strand, in particular the Sä- chain, be counteracted as a result of a faulty sharpening by a too long duration of an action of a sharpness.

The sharpening device according to the invention and / or the portable power tool according to the invention should / should not be limited to the application and embodiment described above. In particular, the sharpening device according to the invention and / or the portable power tool according to the invention may have a number deviating from a number of individual elements, components and units and method steps referred to herein in order to fulfill a mode of operation described herein. In addition, in the value ranges indicated in this disclosure, values lying within the stated limits are also to be disclosed as disclosed and used as desired.

drawing

Further advantages emerge from the following description of the drawing. In the drawings, embodiments of the invention are shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Show it:

Fig. 1 shows a portable power tool according to the invention, in particular a chainsaw, with an inventive

Sharpening device in a schematic representation,

Fig. 2 is a detail view of Schärfvorrichtu invention

a state arranged on a housing of the portable power tool in a schematic representation,

3 is a further detail view of the sharpening device according to the invention in a schematic representation,

Fig. 4 is a force-time diagram in which a sharpening power of the sharpening device according to the invention in response to a FIG. 5 is a detailed view of an alternative invention. FIG

Scharfvorrichtung in a schematic representation and Fig. 6 is a detailed view of a fluid damper element of the alternative sharpening device according to the invention in a schematic representation.

Description of the embodiments

FIG. 1 shows a portable power tool 12a with a sharpening device 10a. The sharpening device 10a is preferably provided for sharpening a cutting strand 18a of the portable power tool 12a in a state arranged on the portable power tool 12a. The portable one

Machine tool 12a is designed as a chain saw. However, it is also conceivable that the portable power tool 12a has another, a skilled person appear appropriate design, such as a configuration as a chainstamp, as a sword saw o. The like. The portable power tool 12a shown in Figure 1 is designed as a wired chainsaw. However, it is also conceivable that the portable power tool 12a is alternatively designed as a battery-operated chain saw. The portable power tool 12a has a housing 48a at least for receiving a drive unit 50a, in particular an electric motor unit, and an output unit 52a, in particular a gear unit, of the portable power tool 12a. However, it is also conceivable for the portable power tool 12a to be decoupled from the output unit 52a and for the drive unit 50a, in particular a drive pinion 66a of the drive unit 50a, to drive the cutting strand 18a directly into the cutting strand 18a or for the drive unit 50a to be one of The drive unit 50a and the output unit 52a act together to drive the cutting strand 18a in a manner already known to a person skilled in the art, as an embodiment as an internal combustion engine unit, as a hybrid motor unit or the like. The cutting strand 18a is arranged in a state arranged on the portable power tool 12a in a manner already known to a person skilled in the art on a guide unit 54a, in particular a guide bar, of the portable power tool 12a, in particular movably mounted thereon. The guide unit 54a can be fixed to the housing 48a of the portable power tool 12a in a manner already known to a person skilled in the art. Furthermore, the portable power tool 12a has a switch-on device 58a arranged on the main handle 56a for commissioning the portable power tool 12a, in particular for energizing the drive unit 50a designed as an electric motor unit. The portable power tool 12a comprises at least one strap handle 60a for guiding the portable power tool 12a. The portable power tool 12a has at least one safety switching device 62a for deactivating the drive unit 50a in a so-called kick-back. The safety switching device 62a has a configuration already known to a person skilled in the art.

FIG. 2 shows a detailed view of the sharpening device 10a. In the embodiment of the portable power tool 12a with the sharpener 10a shown in Figs. 1 and 2, the sharpener 10a is disposed on the housing 48a in a driving area of the portable power tool 12a. In the drive region of the portable power tool 12a, in particular at least one drive pinion 66a of the drive unit 50a is arranged, which is intended to engage in a drive of the cutting strand 18a in the cutting strand 18a. However, it is also conceivable for the sharpening device 10a to be arranged at another position of the portable power tool 12a which appears expedient to a person skilled in the art, such as, for example, on the guide unit 54a on a detachably mountable on the guide unit 54a

Cutting string protective cover o. The like. The sharpening device 10a may be formed as an integral part of the portable power tool 12a or be designed as a retrofit kit, which can be subsequently arranged on the portable power tool 12a. In an embodiment of the sharpening device 10a as a retrofit kit, the portable power tool 12a preferably comprises at least one interface (not shown here in detail), by means of which the sharpening device direction 10a, in particular tool-free, on the portable power tool 12a can be arranged.

The sharpening device 10a for the portable power tool 12a comprises at least one grinding unit 14a which, for sharpening at least one cutting element 16a of the cutting strand 18a, in particular a saw chain, of the portable power tool 12a has at least one movably mounted grinding element 20a. The grinding element 20a is preferably designed as a grindstone. However, it is also conceivable that the grinding element 20a has another embodiment that appears appropriate to a person skilled in the art. The

Sanding element 20a is in particular pivotally mounted on the housing 48a. The sharpening device 10a comprises at least one actuating unit 22a for a movement of the at least one grinding element 20a relative to the cutting strand 18a. As a result of an action of an operator force on the operating unit 22a, in particular on an actuating element 64a of the actuating unit 22a, that is

Abrasive element 20a relative to the cutting strand 18a, in particular on the cutting strand 18a, movable. The actuating element 64a is movable, in particular pivotable, arranged on the housing 48a. The actuating element 64a is preferably designed as an actuating lever. However, it is also conceivable that the actuating element 64a another, a person skilled in the appear appropriate design, such as a configuration as a translationally movably mounted push button, as a slide, as a touch-sensitive actuator, wherein a signal of the touch-sensitive actuating element for driving an actuator usable is, as a knob o. The like.

The sharpening device 10a comprises at least one limiting unit 24a at least for limiting a sharpening force which can be exerted on the at least one cutting element 16a during a sharpening operation by means of the at least one grinding element 20a. The limiting unit 24a is preferably connected in terms of motion with the actuating unit 22a. Preferably, at least the actuating element 64a is arranged on a motion transmission element 34a of the limiting unit 24a, in particular fixed thereto. Preferably, the actuating unit 22a, in particular the actuating element 64a, at least partially in one piece with the limiting unit 24a, in particular with the motion transmitting member 34a, formed. The at least one limiting unit 24a is intended, in particular in addition to limiting the sharpening force, to limit a duration of an action of the sharpening force which can be exerted on the at least one cutting element 16a by means of the at least one grinding element 20a. The limiting unit 24a comprises at least one mechanical force converter 26a and / or electronics 28a (only indicated by dashed lines in FIGS. 1 and 2) for limiting the sharpening force and the duration of the action of the sharpening force. The limiting unit 24a may be at least partially designed as an electronic limiting unit 24a and / or at least partially as a mechanical limiting unit 24a. In an embodiment of the limiting unit 24a as at least partially electronic limiting unit 24a, it is conceivable that the sharpening force by means of a sensor element (not shown here), in particular by means of a force sensor, the limiting unit 24a and / or the duration of an action of the sharpening force by means of one, in particular electronic, timer (not shown in detail here) of the limiting unit 24a is monitored and / or detected, wherein for example based on signals of the sensor element and / or the timer, a control of at least one actuator of the limiting unit 24a takes place, the grinding element 20a relative to Cutting element 16a moves, in particular the grinding element 20a with a predetermined sharpness of the

Cutting element 16a presses for a predetermined duration of an action of the predetermined sharpening force. Preferably, the electronics 28a of the limiting unit 24a, in particular in an at least partial electronic embodiment of the limiting unit 24a, at least one Steuerelect- electronics, the at least one processor unit and at least one memory unit and at least one stored in the memory unit operating program for controlling at least one actuator of Limiting unit 24a has. The electronics 28a of the limiting unit 24a preferably comprises, in particular in the case of an at least partial electronic configuration of the limiting unit 24a, at least the sensor element for detecting a force characteristic of the grinding element 20a and / or a timer for monitoring and / or controlling a duration of an action of the sharpening force , In the exemplary embodiment illustrated in FIGS. 1 and 2, the delimiting unit 24a is preferably designed as a purely mechanical delimiting unit 24a, in particular as a mechanical function independently of the electronics 28a Limiting unit 24a. The limiting unit 24a is preferably designed such that the sharpening force and the duration of an action of the sharpening force have an at least essentially reciprocal proportionality to one another, in particular with a constant maximum movement distance.

The limiting unit 24a has at least one fluid damper element 30a, 32a at least for damping an operator force that can be exerted on the limiting unit 24a by an operator from the actuating unit 22a. Preferably, an at least substantially reciprocal proportionality between the sharpening force and the duration of an action of the sharpening force is determined by a proportional relationship of a fluid damper force of the at least one fluid damper element 30a, 32a and a stroke speed of the piston rod 74a, 76a of the at least one fluid damper element 30a, 32a realizable. In the exemplary embodiment illustrated in FIGS. 1 and 2, the limiting unit 24a comprises at least two fluid damper elements 30a, 32a. The at least two fluid damper elements 30a, 32a are connected in parallel. However, it is also conceivable that the limiting unit 24a has one of one or two different number of fluid damper elements 30a, 32a and / or that the fluid damper elements 30a, 32a are connected in series. The at least two fluid damper elements 30a, 32a preferably have an analogous configuration, so that a description of at least one of the fluid damper elements 30a, 32a can be transferred to the further one of the fluid damper elements 30a, 32a. For the sake of simplicity, in the following description of an indication of a function and / or mode of operation of the fluid damper elements 30a, 32a, reference will only be made to one of the fluid damper elements 30a, 32a.

The at least one fluid damper element 30a, 32a can be designed as a gas pressure damper element or as a fluid pressure damper element, in particular as an oil pressure damper element. The at least one fluid damper element 30a, 32a has in particular a configuration already known to a person skilled in the art. The at least one fluid damper element 30a, 32a is preferably arranged with one end on the actuating element 64a, in particular fixed thereto. Preferably, the fluid damper element 30a, 32a is provided with a piston housing 68a, 70a of the fluid damper element 30a, 32a on the beta element. arranged element 64a, in particular fixed to this. The at least one fluid damper element 30a, 32a is preferably arranged with a further end on an actuating extension 72a of the delimiting unit 24a, in particular fixed thereto. Preferably, the fluid damper element 30a, 32a with a movably mounted piston rod 74a, 76a of the Fluiddämpferele- element 30a, 32a arranged on the actuating extension 72a, in particular fixed thereto. The actuating extension 72a is preferably arranged on a, in particular pivotally mounted, motion transmission element 34a of the delimiting unit 24a, in particular fixed thereto. The actuating extension 72a is preferably fixed in a rotationally fixed manner to the motion transmission element 34a of the limiting unit 24a. It is also conceivable that the actuating projection 72a is formed integrally with the motion transmission element 34a. The actuating extension 72a has, in particular, a main axis of extension which, in particular in a state of the actuating extension 72a arranged on the motion transmission element 34a, extends transversely to a main extension axis of the motion transmission element 34a. Preferably, on the motion transmission element 34a, on which the actuating extension 72a is arranged, the grinding element 20a is arranged, in particular fixed thereto. The grinding member 20a is preferably movable together with the movement transmitting member 34a.

The limiting unit 24a has at least two movement transmission elements 34a, 36a, in particular levers, which are pivotable and / or rotatable relative to one another and which are movable relative to one another by means of at least the fluid damper element 30a, 32a of the limiting unit 24a, wherein the grinding element 20a adjoins at least one the motion transmission elements 34a, 36a is arranged, in particular on the motion transmission element 34a of the motion transmission elements 34a, 36a, on which the actuating extension 72a is arranged. However, it is also conceivable that the boundary unit 24a has one of two different numbers of movement transmission elements 34a, 36a. The motion transmitting elements 34a, 36a preferably form the force transducer 26a of the limiting unit 24a. The motion transmission elements 34a, 36a are formed in the embodiment shown in Figures 1 and 2 as a lever which are pivotally movable about a pivot axis 78a of the limiting unit 24a. preferential way, the pivot axis 78a forms a common axis of movement of the motion transmission elements 34a, 36a. The pivot axis 78a preferably runs at least substantially parallel to a rotation axis 80a of the drive pinion 66a. The motion transmission elements 34a, 36a are pivotally mounted relative to each other about the pivot axis 78a. One of the motion transmission elements 34a, 36a, in particular the further motion transmission element 36a, which is different from the motion transmission element 34a on which the actuation extension 72a is arranged, is connected, in particular fixed thereto or in one piece, to the actuation element 64a of the actuation unit 22a trained with this. Preferably, the further motion transmission element 36a is connected at one end to the actuating element 64a and / or the fluid damper element 30a, 32a, and at another end the further motion transmission element 36a is connected to a bearing element 82a defining the pivot axis 78a, in particular bearing bolts, of the limiting unit 24a , The motion transmitting member 34a on which the actuating projection 72a is disposed is connected at one end to the bearing member 82a, and is urged at another end with a spring force of a return spring member 38a of the limiting unit 24a. The limiting unit 24a has at least the return spring element 38a for returning the grinding element 20a into a position

Starting position and the at least one fluid damper element 30a, 32a at least to an attenuation of an operator exercisable by the operator of the operating unit 22a on the limiting unit 24a operator force, wherein a maximum spring force of the return spring element 38a is greater than a maximum fluid damper force to one of the operator force of a Operator's independent extension movement of a piston rod 74a, 76a of the fluid damper element 30a, 32a.

The limiting unit 24a has at least one retaining element 40a which is provided to hold at least one of the motion transmission elements 34a, 36a, in particular the further motion transmission element 36a of the limiting unit 24a in an unactuated position if there is no exceeding of an actuating force limit value (see FIG. , The holding element 40a is preferably movable, in particular pivotable, mounted. Preferably, the retaining element 40a against a spring force of a retaining spring 84a the limiting unit 24a movably mounted. However, it is also conceivable that the holding element 40a itself is designed resiliently. The holding element 40a is preferably designed as a pivotably mounted latching element. The holding element 40a preferably acts to hold the further movement-transmitting element 36a and / or the actuating element 64a with one

Retaining extension 86a of the further motion transmission element 36a and / or the actuating element 64a together. Preferably, when an operating force limit value is exceeded, a decoupling of the holding element 40a and the further motion transmission element 36a and / or the actuating element 64a, in particular the holding extension 86a and the holding element 40a, to release or allow movement of the further motion transmitting member 36a and / or the actuator 64a , However, it is also conceivable for the actuating force limit value to be monitored by means of a sensor element and for the holding element 40a to be actuated by the electronics 28a as a function of a sensor signal of the sensor element, in particular to enable movement of the further motion transmission element 36a and / or of the actuating element 64a to enable. Other embodiments of the retaining element 40a which appear appropriate to a person skilled in the art are likewise conceivable.

The sharpening device 10a comprises at least one stop variation unit 42a for changing a position of a mechanical stop element 44a of the limiting unit 24a as a function of wear of the at least one grinding element 20a and / or of the at least one cutting element 16a (see FIG. The stopper member 44a is particularly provided for limiting movement of the motion transmitting member 36a on which the grinding member 20a is disposed and / or for the return spring member 38a. The stop variation unit 42a preferably comprises at least one resilient detent element 88a, which interacts with the stop element 44a, in particular is fixed to the stop element 44a. The latching element 88a preferably engages in at least one latching recess 90a, 92a, 94a of the stopper variation unit 42a in order to fix the stopper element 44a in one position. The latching element 88a is preferably designed as a leaf spring, which has a latching extension. With a decrease in a material thickness of the grinding element 20a as a result of wear, a change in particular maximum distance between the grinding element 20a and the cutting strand 18a and in particular as a result a maximum compression distance of the return spring element 38a, so that a force acting on the stop element 44a spring force of the return spring element 38a changes depending on a wear of the grinding element 20a, in particular increases. Preferably, the latching element 88a is movable in response to a magnitude of acting on the stop element 44a spring force of the return spring element 38a in a further recess 90a, 92a, 94a of the Anschlagvariationseinheit 42a to change a position of the stopper member 44a, in particular in response to wear of the Grinding elements 20a. The stop element 44a is preferably mounted translationally displaceable, in particular by means of the latching element 88a. The sharpening device 10a comprises at least one dispensing unit 46a which, depending on a position of the mechanical stop element 44a, outputs wear information to an operator. The output unit 46a can be designed as a haptic, as an acoustic and / or as an optical output unit 46a. Preferably, the latching element 88a and / or the stopper element 44a is connected to a color slider (not shown in detail here) of the output unit 46a, so that the color-dependent slider is moved as a result of a movement of the latching element 88a and / or the stop element 44a a color of the colored slider visible by a display opening is changed, in particular in order to output to a user wear information of the grinding element 20a and / or of the cutting strand 18a. To perform a grinding operation by means of the sharpening device 10a, the actuating element 64a can be actuated by an operator. When an operating force limit value of an actuating force exerted by the operator on the actuating element 64a is exceeded, the retaining element 40a and the actuating element 64a and / or the further movement transmission element 36a are disengaged. The actuator 64a is together with the other motion transmitting member 36a to the

Pivot axis 78a pivotable. The movement of the actuating element 64a together with the further motion transmission element 36a is transferable by means of the at least one fluid damper element 30a, 32a to the movement transmission element 34a, on which the grinding element 20a is arranged. The motion transmitting member 36a is pivotable about the pivot axis 78a. As a result of a pivoting movement of the movement transmission element 36a, the return spring element 38a is compressible about the pivot axis 78a, and the grinding element 20a can be brought into contact with the cutting strand 18a, in particular with the cutting element 16a. The movement transmission element 34a is pivotable together with the actuating element 64a and the further motion transmission element 36a about the pivot axis 78a until the at least one fluid damper element 30a, 32a abuts against a housing stop 96a of the limiting unit 24a, in particular on the housing 48a of the portable power tool 12a.

The housing stop 96a is preferably arranged such that a residual stroke of the piston rod 74a, 76a is ensured when the at least one fluid damper element 30a, 32a abuts against the housing stop 96a. After abutment of the fluid damper element 30a, 32a on the housing stop 96a, an actuation force exerted by the operator on the actuation element 64a can be supported via the further motion transmission element 36a and the at least one fluid damper element 30a, 32a on the housing 48a of the portable power tool 12a. The motion transmission element 34a, on which the grinding element 20a is arranged, is due to a cancellation and / or reduction of a force on the at least one

Fluid damper element 30a, 32a on the motion transmitting member 34a by the return spring member 38a movable to an initial position in which the grinding member 20a is arranged relative to the cutting strand 18a spaced. As a result of the above-described embodiment of the sharpening device 10a and an interaction of the individual components of the sharpening device 10a, a sharpening force and a duration of an action of the sharpening force on the cutting strand 18a, in particular on the cutting element 16a, can advantageously be limited by the limiting unit 24a. To ensure complete recovery of the further motion transmission element 36a and the actuating element 64a to an initial position, the limiting unit 24a preferably has at least one spring element 98a. The spring element 98a is arranged with one end on the further motion transmission element 36a or on the actuating element 64a, in particular fixed thereto. With another end, the spring element 98a is arranged on the housing 48a of the portable power tool 12a, in particular fixed thereto. The spring element 98a is preferably designed as a tension spring. However, it is also conceivable that the spring element 98a has another, a skilled person appear appropriate design. FIG. 4 shows a force-time diagram in which a sharpening power of the

Sharpening device 10a is shown as a function of a speed of an action of an operating force of an operator on the operating unit 22a and / or the limiting unit 24a as an area under a curve. If the further motion transmission element 36a, together with the fluid damper element 30a, 32a, is rapidly moved in the direction of the housing stop 96a, a large sharpening force is exerted on the cutting element 16a in a short period of time by means of the grinding element 20a as a result of the above-explained configuration and mode of operation of the limiting unit 24a (see left graph 100a in force-time diagram). If the further movement transmission element 36a, together with the fluid damper element 30a, 32a, slowly moves in the direction of the housing stop 96a, a small sharpening force is exerted on the cutting element 16a in a long period of time by means of the grinding element 20a as a result of the above-described configuration and mode of operation of the limiting unit 24a (see right graph 102a in the force-time diagram). The product of applied sharpness and the duration of a

The effect of the sharpening force on the cutting element 16a, in particular the sharpening power or the sharpening effect, which is represented by the areas below the respective graph 100a, 102a, is at least substantially the same under both graphs 100a, 102a. Advantageously, a constant result of a sharpening operation can be achieved, which is preferably independent of a variation of an action of an operator force.

In the figures 5 and 6, a further embodiment of the invention is shown. The following descriptions and the drawings are essentially limited to the differences between the exemplary embodiments, wherein, with regard to identically named components, in particular with regard to components having the same reference numbers, in principle also to the drawings and / or the description of the other embodiments, in particular FIGS to 4, can be referenced. In order to distinguish the exemplary embodiments, the letter a is the reference symbol of the exemplary embodiment in FIGS adjusted to 4. In the exemplary embodiments of FIGS. 5 and 6, the letter a is replaced by the letter b.

FIG. 5 shows a detailed view of an alternative sharpening device 10b for portable machine tools. The sharpening device 10b is analogous to that in the

Description of Figures 1 to 4 described sharpening device 10a on a portable machine tool (not shown here) can be arranged or arranged. The sharpening device 10b comprises at least one grinding unit 14b, which is used to sharpen at least one cutting element (not shown here in detail) of a cutting strand (not shown here in detail), in particular one

Saw chain, the portable power tool has at least one movably mounted grinding element 20b. The sharpening device 10b further comprises at least one actuating unit 22b for moving the at least one grinding element 20b relative to the cutting strand and at least one boundary unit 24b for at least limiting a sharpening force that can be exerted on the at least one cutting element during a sharpening operation by the at least one grinding element 20b. The at least one limiting unit 24b is intended, in particular in addition to limiting the sharpening force, to limit a duration of an action of the sharpening force which can be exerted on the at least one cutting element by means of the at least one sliding element 20b. The sharpening device 10b shown in FIG. 5 has an at least substantially analogous configuration to the sharpening device 10a shown in FIGS. 1 to 3. The sharpening device 10b shown in FIG. 5 preferably differs from the sharpening device 10a shown in FIGS. 1 to 3 by a configuration of the actuating unit 22b and the limiting unit 24b. The actuating unit 22b comprises at least one actuating element 64b, which is designed as a translationally mounted snap button. The limiting unit 24b comprises at least two movement transmission elements 34b, 36b which are pivotable and / or rotatable relative to one another and which are movable by means of at least one fluid damper element 30b of the limiting unit 24b, the grinding element 20b being arranged on at least one of the motion transmission elements 34b, 36b. The actuating element 64b is arranged on the fluid damper element 30b, in particular integrated therein (compare FIGS. 5 and 6). Preferably, one of the motion transmission elements 34b, 36b is designed as a gear wheel, in particular the further motion transmission element 36b. The motion transmitting member 34b, on which the grinding member 20b is fixed, is formed as a pivotally mounted lever with a gear portion 104b. The gear portion 104b is provided for cooperation with the other gear transmission member 36b. A piston rod 74b of the fluid damper member 30b has a gear portion 106b provided for cooperation with the other gear transmission member 36b formed as a gear. As a result of a translational movement of the piston rod 74b, the motion transmission element 36b designed as a gear wheel is rotatable. As a result of a rotation of the movement transmission element 36b, which is further in the form of a gearwheel, the motion transmission element 34b designed as a lever is pivotable about a pivot axis 78b. As a result of a pivoting movement of the movement-transmitting element 34b designed as a lever, the grinding element 20b can be pressed against the cutting strand, in particular against the cutting element. With regard to further features and functions of the sharpening device 10b illustrated in FIGS. 5 and 6, reference may be made to the description of the sharpening device 10a shown in FIGS. 1 to 4, which is applicable at least substantially analogously to the sharpening device 10b.

Claims

claims

1. Sharpening device for portable machine tools, in particular for chain saws, having at least one grinding unit (14a, 14b) for sharpening at least one cutting element (16a) of a cutting strand (18a), in particular a saw chain, of the portable machine tool at least one movably mounted grinding element (14a; 20a, 20b) with at least one actuating unit (22a, 22b) for movement of the at least one grinding element (20a, 20b) relative to the cutting strand (18a), and with at least one delimiting unit (24a, 24b) at least for a limitation during a sharpening operation by means of the at least one grinding element (20a; 20b) on the at least one cutting element (16a) exercisable sharpening force, characterized in that the at least one limiting unit (24a; 24b), in particular in addition to limiting the sharpening force, is provided for a duration an action of the at least one grinding element (20a, 20b) on d as at least one cutting element (16a) exercisable sharpening force limit.

2. sharpening device according to claim 1, characterized in that the

Limiting unit (24a, 24b) comprises at least one mechanical force transducer (26a; 26b) and / or electronics (28a; 28b) for limiting the sharpening force and the duration of an action of the sharpening force.

3. sharpening device according to claim 1 or 2, characterized in that the limiting unit (24a, 24b) is formed such that the sharpening force and the duration of an action of the sharpening force have an at least substantially reciprocal proportionality to each other.

Sharpening device according to one of the preceding claims, characterized in that the limiting unit (24a; 24b) at least one fluid damper element (30a, 32a; 30b) at least to a damping by the operator of the operating unit (22a; 22b) on the limiting unit (24a; 24b) exercisable operator force.

Sharpening device according to one of the preceding claims, characterized in that the limiting unit (24a, 24b) has at least two movement transmission elements (34a, 36a; 34b, 36b) which are pivotable and / or rotatable relative to each other, in particular levers, which by means of at least one fluid damper element (30a , 32a; 30b) of the limiting unit (24a; 24b) are movable, wherein the grinding member (20a; 20b) is disposed on at least one of the motion transmitting members (34a, 36a; 34b, 36b).

Sharpening device according to one of the preceding claims, characterized in that the limiting unit (24a) at least one return spring element (38a) to a provision of the grinding element (20a) in a starting position and at least one fluid damper element (30a, 32a) at least to a damping by a user a maximum spring force of the return spring element (38a) is greater than a maximum fluid damper force to an operator's operator independent extension movement of a piston rod (74a, 76a) of the fluid damper element (FIG. 30a, 32a).

Sharpening device according to one of the preceding claims, characterized in that the limiting unit (24a) has at least one retaining element (40a), which is provided, at least one movement transmission element (34a, 36a) of the limiting unit (24a) in the absence of exceeding a Operational force limit in an unactuated position.

8. sharpening device according to one of the preceding claims, characterized by at least one Anschlagvariationseinheit (42 a) for changing a position of a mechanical stop element (44 a) of the limiting unit (24 a) in response to wear of the at least one grinding element (20 a) and / or at least a cutting element (16a).

9. sharpening device according to claim 8, characterized by at least one output unit (46 a) which outputs a wear information in dependence on a position of the mechanical stop element (44 a) an operator.

10. Portable machine tool, in particular chain saw, with a sharpening device according to one of the preceding claims.