EP3056316B1 - Handheld machine tool - Google Patents

Description

State of the art

The invention is based on a handheld power tool according to the preamble of claim 1.

A handheld power tool, in particular a screwdriver hammer, with a gear arrangement, a hammer mechanism and a tool spindle has already been proposed. Out DE 101 49 216 A1 a hand-held power tool with a mechanical hammer mechanism is known which has a hammer that can be driven by strikingly via a driver unit mounted on an intermediate shaft. In EP 1 050 381 A2 a handheld power tool with a rotary impact function and a drilling function is disclosed.

Disclosure of the invention

The invention is based on a hand-held power tool, in particular a screwdriver hammer, with a gear arrangement, a hammer mechanism and a tool spindle.

The hammer mechanism has a hammer which at least partially encloses the tool spindle in at least one plane. A “gear arrangement” should be understood to mean an arrangement which has at least one gear stage. The gear stage is advantageously designed as an angular gear, as a bevel gear and / or as another gear stage that appears sensible to a person skilled in the art. The gear stage is particularly advantageously designed as a planetary gear stage. A “hammer mechanism” should be understood to mean an impact mechanism with at least one linearly moved hammer. Advantageously, the hammer mechanism moves the hammer resiliently and / or pneumatically and / or hydraulically by means of a link device, by means of a wobble bearing and / or advantageously by means of an eccentric element. The hammer mechanism is thus designed as a link mechanism, as a wobble bearing mechanism and / or as an eccentric mechanism. A "link mechanism" should be understood to mean a hammer mechanism with a link device. A link device generates a linear movement between at least two areas by means of elements that can be moved on a mechanically limited endless path. A "wobble bearing mechanism" should be understood to mean a bearing with a finger that is connected to a drive rotation element of the hammer mechanism and the bearing plane of which deviates from a plane that is perpendicular to the axis of rotation of the drive rotation element. An “eccentric hammer mechanism” should be understood to mean a hammer hammer mechanism which is provided to generate a linear movement perpendicular to the axis of rotation of the rotational movement from a rotational movement. The eccentric hammer mechanism preferably has an eccentric element which is connected to the rotary drive element in a rotationally fixed manner. A "hammer mechanism" is not to be understood as a detent mechanism in which a rotatable detent disc is permanently mechanically connected to the hand tool housing in the axial direction and in which the detent disc interacts to generate a pulse with a detent disc mechanically permanently connected to the tool spindle. A "detent hammer mechanism" is in particular a hammer mechanism in which an impact-generating detent disk can be driven to rotate. An axial toothing of the detent disk causes an axial movement of the tool spindle. A “tool spindle” should be understood to mean a shaft of the handheld power tool which, in at least one operating state, transmits a rotary movement to a tool fastening device of the handheld power tool. An axis of rotation of the tool spindle preferably lies on an axis of rotation of an insert tool and / or the tool fastening device. In at least one operating state, the tool spindle particularly advantageously transmits a rotary movement and an impact movement to the tool fastening device. At least part of the tool spindle is particularly advantageously connected directly to the tool fastening device. The tool spindle preferably has a fastening for the tool fastening device. Alternatively, the tool spindle can be at least partially in one piece with the tool fastening device be trained. The tool fastening device is advantageously designed as a tool chuck, as a hexagonal receptacle, as an SDS receptacle (Special Direct System from Robert Bosch GmbH) and / or as another tool fastening device that appears useful to a person skilled in the art. “Provided” is to be understood in particular to be specifically equipped and / or designed. The tool spindle advantageously extends at least partially through the hammer in the direction of the axis of rotation of the tool spindle. Particularly advantageously, the tool spindle extends completely through the club. The hammer preferably encloses the tool spindle in at least one plane by 360 °. The phrase "encloses 360 ° in at least one plane" is to be understood in particular to mean that the hammer radially envelops at least one point on the tool spindle in at least one plane.

The design of the handheld power tool according to the invention advantageously makes it possible to achieve a tool spindle with a low mass and thus provide a particularly light and compact handheld power tool with high performance.

In an advantageous embodiment of the invention, it is proposed that the hammer strikes the tool spindle in at least one operating state. The beater advantageously transmits an impact pulse to at least part of the tool spindle, the tool spindle advantageously transmitting the impact pulse to a tool fastening device of the handheld power tool. The tool fastening device preferably transmits the impact pulse to an insert tool. Alternatively and / or additionally, the bat strikes an impact transmission device, such as a striker, or directly an insert tool of the hand machine tool. The impact transmission device transmits an impact movement directly to an insert tool. For this purpose, the impact transmission device is arranged, for example, at least partially coaxially within the tool spindle. As a result of the hammer hitting the tool spindle, the tool spindle can advantageously transmit an impact movement and a rotary movement in combination to a tool fastening device, whereby an inexpensive, universally applicable device is advantageous and constructively simple tool fastening device can be used and, in turn, installation space can be saved.

In a further embodiment, it is proposed that the hammer mechanism has a spring-elastic lever element which is mounted pivotably about a pivot axis and is provided to drive the hammer of the hammer mechanism in at least one operating state. A “lever element” is to be understood in particular as a movable element on which at least two torques act at a distance, advantageously at a different distance, from the pivot axis. The lever element is preferably pivotable about a pivot axis which is oriented perpendicular to the axis of rotation of the tool spindle. The lever element is particularly advantageously configured to be rotationally asymmetrical and / or can be moved by less than 360 ° about an axis of rotation. The term "resiliently" is to be understood in particular to mean that at least one point of the lever element is deflected by at least 1 mm relative to another point of the lever element during an operating state. The lever element is advantageously at least partially made of spring steel. The term “drift” is to be understood in particular to be accelerating. An effective and inexpensive hammer mechanism can be implemented in a structurally simple manner by means of the lever element.

In an advantageous embodiment of the invention, it is proposed that the racket is freely movable in a main working direction in at least one operating state. The racket is preferably movable by the lever element. In this context, “freely movable” is to be understood in particular to mean that the racket is decoupled from components over at least one distance in the main working direction, with the exception of sliding and / or rolling friction in a guide. In particular, a “main working direction” should be understood to mean an impact pulse direction of the hammer mechanism. The racket, which can be moved freely in at least one operating state, can achieve a particularly high impact energy and, at the same time, comfortable and, in particular, low-vibration operation.

According to the invention, the tool spindle has a rotary driving contour which is provided to produce an axially displaceable and rotationally fixed connection along an axis of rotation. The rotary drive contour transfers rotational forces. The rotary driving contour is designed as a rotary driving contour that appears sensible to the person skilled in the art, such as in particular a spline shaft profile and / or advantageously as a toothing. According to the invention, the tool spindle is designed in two parts and the rotary drive contour connects the two parts of the tool spindle with one another. Due to the rotary drive contour, a ratio between hammer and spindle mass can advantageously be optimally selected and the tool spindle can be axially decoupled from the gear arrangement, whereby wear, in particular on a planetary gear carrier of the gear arrangement, can be minimized.

Furthermore, it is proposed that the gear arrangement has at least one sun gear which, in at least one operating state, is non-rotatably connected to at least one part of the hammer mechanism in a non-rotatable manner, in particular directly, i.e. without interposed further components, which enables a particularly simple and space-saving construction. The sun gear is advantageously connected non-rotatably to a rotary drive element of the hammer mechanism.

Furthermore, an electric motor and a battery connection unit are proposed, which are provided to supply the electric motor with energy. For this purpose, the battery connection unit is preferably connected to a battery unit in an operationally ready operating state. A “battery connection unit” is to be understood in particular as a unit which is provided to establish contact with the battery unit. The connection unit advantageously produces an electrical and a mechanical contact. An “battery unit” is to be understood as meaning, in particular, a device with at least one accumulator which is provided to supply the handheld power tool with power independently of the mains. This makes it possible to implement a handheld power tool that is particularly convenient and can be used independently of a power supply system. As an alternative, the hand-held power tool can also be equipped with another motor that appears sensible to a person skilled in the art, such as in particular one Mains connection having electric motor or a compressed air motor, can be operated.

It is also proposed that the gear arrangement have a gear stage which is designed as a planetary gear stage. The planetary gear stage has at least one sun gear, a ring gear, at least one planet gear and / or a planet gear carrier. Thanks to the planetary gear stage, an advantageous reduction can be achieved in a particularly space-saving manner.

It is further proposed that the hammer mechanism has a releasable, in particular mechanically releasable coupling device which is provided to transmit a rotary movement. In at least one operating state, the coupling device preferably connects an impact mechanism shaft of the hammer mechanism and at least part of the gear arrangement in a rotationally fixed manner. A “releasable coupling device” is to be understood in particular as a coupling device which transmits a rotary movement in at least one operating state and which interrupts a transmission of the rotary movement in at least one operating state. “Transferring a rotary movement” is to be understood to mean, in particular, transferring a speed and / or a torque. The detachable coupling device can advantageously switch off the hammer mechanism and thus achieve a handheld power tool that can advantageously be used as a screwdriver.

It is also proposed that the coupling device is provided to be closed by a force transmitted via the tool spindle. The coupling device is preferably provided to be closed by a force acting in the axial direction of the tool spindle. Due to the coupling device that can be closed via the tool spindle, the hammer mechanism can advantageously be switched on automatically during a drilling process and switched off when idling, which enables less wear and tear and convenient operation.

In an advantageous embodiment of the invention, it is proposed that the handheld power tool have a torque setting unit with a coupling device, which is provided for the purpose of applying a maximum torque transmitted via the tool spindle in at least one operating state limit. The coupling device is advantageously releasable. The “maximum torque” is preferably a torque that the tool spindle can transmit to an insert tool in an operation, in particular before a coupling device opens automatically. The coupling device is preferably designed as a device with spring-loaded or spring-loaded latching elements, such as in particular balls. In principle, however, other devices that appear useful to a person skilled in the art are also conceivable. The locking elements can be loaded with a spring force in an axial and / or preferably in a radial direction. By limiting the maximum torque, undesirably high torques can be prevented.

It is also proposed that the handheld power tool have an operating element by means of which the coupling device can be actuated. At least the operator can advantageously operate the coupling device by means of the operating element and / or by means of the tool spindle. Alternatively and / or additionally, a sensor unit and an actuation unit can actuate the coupling device at least partially automatically on the basis of material properties of a workpiece. The coupling device of the torque setting unit and the coupling device of the hammer mechanism preferably each have one and / or a common operating element. “Actuate” is to be understood in particular to open and / or close the coupling device, as a result of which the percussion operation can be conveniently switched on and off by the operator and, in particular, the coupling device of the torque setting unit can be permanently closed in a drilling operation.

It is further proposed that the hammer mechanism has a rotary drive element with an axis of rotation which is arranged coaxially to at least part of the tool spindle. A “rotary drive element” is to be understood in particular as an element which executes a rotary movement in at least one operating state and which moves at least one further element of the hammer mechanism. The rotary drive element is advantageously designed as a shaft, particularly advantageously as a hollow shaft. The term “coaxial” is to be understood in particular to mean that at least part of the tool spindle and the rotary drive element are in at least one operating state are driven to rotate about a common axis of rotation. Preferably, at least a part of the tool spindle and the rotary drive element can be rotated relative to one another about the same axis of rotation. The hand-held power tool is particularly advantageously designed without an intermediate shaft. “Without an intermediate shaft” is to be understood in particular to mean that all shafts of the handheld power tool which transmit a rotary movement at least in a drilling operation have a common axis of rotation which advantageously coincides with the axis of rotation of the tool spindle. “At least part of the tool spindle” is to be understood as meaning, in particular, an area of the tool spindle that is directly connected to the tool fastening device. Alternatively and / or additionally, “at least part of the tool spindle” should be understood to mean an area of the tool spindle that is directly connected to the gear arrangement. A particularly compact and, in particular, short design can be achieved by the rotational drive element arranged coaxially with at least one part of the tool spindle. The handheld power tool achieves a particularly high single impact energy, which advantageously leads to particularly good drilling progress.

In a further embodiment, it is proposed that the rotary drive element be designed as a hammer mechanism shaft which envelops at least one area of the tool spindle. A "hammer mechanism shaft" is to be understood in particular as a shaft which transmits a rotary movement to at least one further element of the hammer mechanism in order to generate an impact. Particularly advantageously, the tool spindle and the hammer mechanism shaft rotate at a different angular speed in at least one operating state. The term “envelop” is to be understood in particular to mean that the hammer mechanism shaft largely surrounds the tool spindle in at least one plane, advantageously by 360 °. This plane is advantageously oriented perpendicular to the axis of rotation of the rotary drive element. A particularly space-saving construction can be achieved through a corresponding configuration and the hammer mechanism shaft surrounding the tool spindle can be realized with a small tool spindle mass and a small tool spindle diameter.

It is further proposed that the hammer mechanism has an eccentric element, whereby a mechanically low-wear and powerful handheld power tool can be provided in a structurally simple manner.

It is also proposed that the eccentric element have an axis of rotation which coincides with an axis of rotation of the tool spindle. The term “match” is to be understood in particular to mean that the eccentric element is mounted such that it can rotate about the same axis of rotation as the tool spindle. The eccentric element and at least part of the tool spindle are preferably connected to one another in a rotationally fixed manner. As a result, an intermediate shaft can advantageously be dispensed with and a particularly handy and light handheld power tool can be achieved. In particular, a powerful handheld power tool with a weight including a battery unit of less than 5 kg, advantageously less than 2 kg, particularly advantageously less than 1.5 kg, can be achieved.

In addition, it is proposed that the gear arrangement has at least one gear stage element which is provided to split up a power flow in order to provide different speeds for an impact drive and a rotary drive. A “gear step element” is to be understood as meaning, in particular, a sun gear, a ring gear, a planet gear, another element of the gear arrangement that appears sensible to a person skilled in the art, and / or in particular a planet gear carrier. In this context, “splitting” is to be understood in particular to mean that forces which cause torques act on the gear stage element at at least three points, such as in particular at least one input point and at least two output points. As a result, a speed for a percussion drive can be optimized to a particularly effective number of strokes and thus a particularly large drilling progress can be achieved in a percussion drilling operation.

It is further proposed that the gear arrangement generates at least two output rotary movements in at least one operating state, which have an integer ratio to one another. In at least one operating state, the gear arrangement preferably transmits one of the output rotary movements to the tool spindle and one of the output rotary movements on the hammer mechanism. An “integer ratio” is to be understood in particular as a ratio which lies outside a natural number set. The ratio is preferably outside the natural number set between 2 and 6. An "output rotary movement" is to be understood in particular as a rotary movement which leads to a power output from the gear arrangement. Due to the integer ratio between the two output rotary movements, an advantageous impact pattern can be achieved, which enables a particularly effective impact drilling operation.

In a further refinement, it is proposed that the gear arrangement have at least one ring gear that is mounted so that it can move axially. “Axially movably supported” should be understood to mean, in particular, moveable in a direction parallel to an axis of rotation of the ring gear. The ring gear is advantageously movable in relation to a hand tool machine housing, in relation to at least one planet gear of the same gear stage and / or in relation to at least one planet gear in a further gear stage. It is particularly advantageous that the ring gear can be moved in such a way that it is coupled to at least one planet gear of two different gear stages at the same time and / or one after the other. By means of the axially movably mounted ring gear, a locking clutch and / or an impact shut-off can be implemented in a structurally simple and cost-effective manner.

Furthermore, it is proposed that the handheld power tool have a spring element which, in at least one operating state, exerts a force on the axially movable ring gear, whereby the ring gear is advantageously automatically moved in at least one direction and thus a structurally simple structure is possible.

It is further proposed that the gear arrangement has at least one gear stage which is provided to increase a speed for a percussion drive, whereby an advantageously high percussion rate and thus an effective percussion drilling process can be achieved.

drawing

Further advantages emerge from the following description of the drawings. Two exemplary embodiments of the invention are shown in the drawings. The drawings, 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.

Fig. 1

eine erfindungsgemäße Handwerkzeugmaschine mit einem schematisch dargestellten Antriebsstrang,

Fig. 2

eine Funktionsskizze des Antriebsstrangs aus Figur 1 mit einem Elektromotor, einer Getriebeanordnung und einem Hammerschlagwerk,

Fig. 3

einen schematischen Teilschnitt durch das Hammerschlagwerk der Handwerkzeugmaschine aus Figur 1,

Fig. 4

einen Schnitt durch das Hammerschlagwerk aus Figur 3,

Fig. 5

ein Hebelelement des Hammerschlagwerks aus Figur 3 in einer perspektivischen Darstellung und

Fig. 6

eine Funktionsskizze eines alternativen Ausführungsbeispiels des Antriebsstrangs aus Figur 1.

Show it:

Fig. 1

a handheld power tool according to the invention with a schematically illustrated drive train,

Fig. 2

a functional sketch of the powertrain Figure 1 with an electric motor, a gear arrangement and a hammer mechanism,

Fig. 3

a schematic partial section through the hammer mechanism of the hand machine tool Figure 1 ,

Fig. 4

a section through the hammer mechanism Figure 3 ,

Fig. 5

a lever element of the hammer mechanism Figure 3 in a perspective view and

Fig. 6

a functional sketch of an alternative embodiment of the drive train Figure 1 .

Description of the exemplary embodiments

Figure 1 shows a handheld power tool 10a, which is designed as a cordless hammer drill, in a partially schematic representation. The handheld power tool 10a has a torque setting unit 12a, a gear arrangement 14a, a hammer mechanism 16a, a tool spindle 18a, a battery connection unit 20a, a pistol-shaped handheld power tool housing 22a and an electric motor 24a arranged in the handheld power tool housing 22a. In a front region 28a of the handheld power tool 10a, seen against a main working direction 26a of the handheld power tool 10a, the handheld power tool 10a has a tool fastening device 30a, which is designed as a tool chuck. An insert tool 32a is fastened in the tool fastening device 30a and, when the handheld power tool 10a is in operation, rotates about an axis of rotation 34a of the tool spindle 18a, which extends parallel to the main working direction 26a. The axis of rotation 34a is designed as a main axis of rotation, that is to say several elements of the hand-held power tool 10a can be rotated about this axis of rotation 34a.

An operating element 36a of the torque setting unit 12a is arranged in a ring around the axis of rotation 34a of the tool spindle 18a, between the handheld power tool housing 22a and the tool fastening device 30a. On an upper side 38a of the handheld power tool 10a, that is to say one facing away from the battery connection unit 20a, an operating element 40a is arranged which enables an operator not shown in detail to switch between a drilling or screwdriving operation and a hammer drilling operation.

The electric motor 24a is arranged in a rear region 42a of the handheld power tool housing 22a, that is to say facing away from the tool fastening device 30a. A stator, not shown in more detail, of the electric motor 24a is non-rotatably connected to the handheld power tool housing 22a. The gear arrangement 14a is arranged in a tubular, upper region 44a of the pistol-shaped handheld power tool housing 22a arranged axially to the axis of rotation 34a. A lower region 46a of the handheld power tool housing 22a, which adjoins the upper region 44a at approximately right angles, forms a handle 48a. The battery connection unit 20a is arranged at a lower end of the lower region 46a. In a shown operationally ready state, a battery unit 50a is connected to the battery connection unit 20a. The battery unit 50a supplies the electric motor 24a with energy during operation.

As the Figures 2 and 3 show, the hammer mechanism 16a has a drive rotation element 52a with a rotation axis 34a, which is arranged coaxially to the tool spindle 18a. The rotary drive element 52a is designed as a hammer mechanism shaft 54a. The hammer mechanism shaft 54a surrounds an area the tool spindle 18a, which faces the gear arrangement 14a. The axis of rotation 34a of the hammer mechanism shaft 54a is aligned parallel to the main working direction 26a of the handheld power tool 10a. The tool spindle 18a connects the tool fastening device 30a to the gear arrangement 14a in a rotationally fixed manner along the axis of rotation 34a and is for the most part designed as a solid shaft.

The hammer mechanism 16a is designed as an eccentric hammer mechanism which has an eccentric element 56a. In again Figure 4 shows the section (AA) shown, the eccentric element 56a has an axis of rotation which coincides with the axis of rotation 34a of the tool spindle 18a. The eccentric element 56a is formed by a sleeve, the wall thickness 58a of which increases and decreases continuously over the course of 360 ° around the axis of rotation 34a. The eccentric element 56a is non-rotatably connected to the hammer mechanism shaft 54a and is penetrated by this in the axial direction. The hammer mechanism 16a has an outer eccentric element 60a which is moved by the eccentric element 56a during a percussion drilling operation. The eccentric outer element 60a is designed as an approximately elliptical disk. It has a round bore 62a which is arranged in a region 64a of the outer eccentric element 60a facing away from the handle 48a. In the bore 62a, the eccentric element 56a is movably supported relative to the eccentric outer element 60a by means of a bearing (not shown in detail). Furthermore, the eccentric outer element 60a has an opening 80a which is arranged in a region of the eccentric outer element 60a facing the handle 48a. The opening 80a is penetrated by a resilient lever element 66a. The lever element 66a prevents rotation of the eccentric outer element 60a in the circumferential direction relative to the handheld power tool housing 22a.

The hammer mechanism 16a has a hammer 68a. The lever member 66a drives the beater 68a during a percussion drilling operation. The lever element 66a is designed as an L-shaped bracket made of spring steel in a side view. How Figure 5 shows, the lever element 66a has a horseshoe-shaped region 70a which is penetrated by the tool spindle 18a. The hammer mechanism 16a has a pivot axis 72a fixed to the housing, around which the lever element 66a is tiltable. The pivot axis 72a fixed to the housing is oriented perpendicular to the axis of rotation 34a of the tool spindle 18a.

Also show the Figures 2 and 3 that the striker 68a of the hammer mechanism 16a is freely movable in the main working direction 26a during a free flight phase. The free flight phase is a period of time which begins with an end of an acceleration of the club 68a by the lever element 66a and ends immediately before a stroke. In the event of an impact, the striker 68a transmits an impact pulse to the tool spindle 18a. For this purpose, the hammer 68a strikes a transmission element 74a of the tool spindle 18a. The transmission element 74a is designed as a thickening of the tool spindle 18a, which has a surface 76a on a side facing the hammer 68a. The surface 76a is aligned parallel to a striking surface 78a of the racket 68a. The hammer 68a encloses the tool spindle 18a in planes which are oriented perpendicular to the axis of rotation 34a of the tool spindle 18a by 360 °. The hammer 68a is guided on the tool spindle 18a and is mounted so as to be rotatable about the axis of rotation 34a of the tool spindle 18a with respect to the handheld power tool housing 22a. Alternatively, the racket can also be guided on its outer contour and / or be secured against rotation with respect to the handheld power tool housing.

When the eccentric element 56a is rotated, the eccentric outer element 60a moves perpendicular to the axis of rotation 34a of the tool spindle 18a. A movement of the eccentric outer element 60a moves an end 82a of the lever element 66a that is tiltably arranged in the opening 80a of the eccentric outer element 60a and thereby tilts the lever element 66a. The lever element 66a thereby accelerates the racket 68a from a starting position facing the gear arrangement 14a in the direction of the main working direction 26a, in that a driving end 84a of the lever element 66a presses against a first support surface 86a of the racket 68a. After the acceleration, the racket 68a moves in the main working direction 26a into the free flight phase, in which the driving end 84a of the lever element 66a is arranged in a free area 88a of the racket 68a and is thus decoupled from the racket 68a in the main working direction 26a. At the end of this free flight phase, the striker 68a hits the transmission element 74a of the tool spindle 18a and transmits it Impulse on the tool spindle 18a. The lever element 66a then moves the racket 68a back into the starting position in that the driving end 84a of the lever element 66a exerts a force on a second support surface 90a of the racket 68a, which force is arranged on a different side of the free area 88a in relation to the first support surface 86a. The resilient configuration of the lever element 66a enables the forces acting between the lever element 66a and the striker 68a to develop without jumps.

The gear arrangement 14a has four gear stages, which are designed as planetary gear stages 92a, 94a, 96a, 98a. The four planetary gear stages 92a, 94a, 96a, 98a are arranged one behind the other along the axis of rotation 34a of the tool spindle 18a. The four planetary gear stages 92a, 94a, 96a, 98a each have a ring gear 100a, 102a, 104a, 106a, a sun gear 108a, 110a, 112a, 114a, a planet gear carrier 116a, 118a, 120a, 122a and four planet gears 124a, 126a, 128a, 130a, of which only two are shown. The planet gears 124a of the first planetary gear stage 92a mesh with the sun gear 108a of the first planetary gear stage 92a and the ring gear 100a of the first planetary gear stage 92a and are rotatably mounted on the planetary gear carrier 116a of the first planetary gear stage 92a. The planetary gear carrier 116a of the first planetary gear stage 92a guides the planetary gears 124a of the first planetary gear stage 92a on a circular path around the axis of rotation 34a of the tool spindle 18a. The second planetary gear stage 94a, the third planetary gear stage 96a and the fourth planetary gear stage 98a are constructed accordingly.

The sun gear 108a of the first planetary gear stage 92a is non-rotatably connected to the electric motor 24a and is arranged in the main working direction 26a next to the electric motor 24a, between the tool fastening device 30a and the electric motor 24a. The ring gear 100a of the first planetary gear stage 92a is non-rotatably connected to the handheld power tool housing 22a. The planet carrier 116a of the first planetary gear stage 92a is non-rotatably connected to the sun gear 110a of the second planetary gear stage 94a, the ring gear 102a of which is also connected to the handheld power tool housing 22a. The planetary gear carrier 118a of the second planetary gear stage 94a is non-rotatable with the sun gear 112a of the third planetary gear stage 96a connected. The ring gear 104a of the third planetary gear stage 96a is also non-rotatably connected to the handheld power tool housing 22a during a drilling, screwing or hammer drilling process. Thus, the first, the second and the third planetary gear stages 92a, 94a, 96a each cause a reduction in the direction of the tool fastening device 30a. There is thus likewise a reduction between the sun gear 108a of the first planetary gear stage 92a and the planetary gear carrier 120a of the third planetary gear stage 96a. A ratio of this reduction between a speed of the electric motor 24a and a speed of the tool spindle 18a is approximately 60: 1.

In addition, the person skilled in the art is familiar with the possibilities for switching an alternative transmission ratio between a speed of the electric motor 24a and a speed of the tool spindle 18a. For example, the ring gear 102a of the second planetary gear stage 94a can be connected non-rotatably to the planetary gear carrier 116a of the first planetary gear stage 92a by means of a coupling device, not shown in detail, as an alternative to the handheld power tool housing 22a. The alternative transmission ratio between the speed of a motor speed and the speed of the tool spindle 18a is approximately 15: 1.

The gear arrangement 14a has a gear stage element 132a which divides a power flow. The gear stage element 132a is designed as a common planetary gear carrier 120a, 122a of the third and fourth planetary gear stages 96a, 98a. The tool spindle 18a has a rotary driving contour 134a which produces an axially displaceable and rotationally fixed connection with the gear arrangement 14a, more precisely with the gear stage element 132a, along the axis of rotation 34a. Accordingly, a speed of the tool spindle 18a is picked up on the planetary gear carrier 120a of the third planetary gear stage 96a.

In this example, the rotary driving contour 134a is designed as an internal toothing 136a of the gear stage element 132a and an external toothing 138a of the tool spindle 18a. Alternatively, the tapping could take place on the ring gear of the third planetary gear stage 96a.

Alternatively or in addition to the in Figure 2 Rotary driving contour 134a shown and described above can be as shown in FIG Figure 3 shown a rotary driving contour 140a dividing the tool spindle 18a axially into two parts 142a, 144a. One part 142a of the tool spindle 18a is directly connected to the gear arrangement 14a. The other part 144a of the tool spindle 18a is connected directly to the tool fastening device 30a. The previously described rotary driving contour 134a can be omitted. The part 142a of the tool spindle 18a which is directly connected to the gear arrangement 14a can then be firmly connected in the axial direction to the gear stage element 132a. As a result, a mass of the axially movable part 144a of the tool spindle 18a can be reduced.

The sun gear 114a of the fourth planetary gear stage 98a is non-rotatably connected to the rotary drive element 52a during a hammer drilling operation. Thus, the sun gear 114a of the fourth planetary gear stage 98a is non-rotatably connected to the eccentric element 56a of the hammer mechanism 16a during a hammer drilling process. Alternatively, the ring gear 106a of the fourth planetary gear stage 98a could also be connected to the rotary drive element 52a in a rotationally fixed manner.

The ring gear 106a of the fourth planetary gear stage 98a is mounted such that it can move axially. The gear arrangement 14a has a coupling element 146a, which connects the ring gear 106a of the fourth planetary gear stage 98a in a rotationally fixed and axially displaceable manner to the handheld power tool housing 22a. With this arrangement, the gear arrangement 14a, more precisely the fourth planetary gear stage 98a, generates output rotary movements during a hammer drilling operation from the two power flows of the common planetary gear carrier 120a, 122a of the third and fourth planetary gear stages 96a, 98a, which have an integer ratio to one another. Furthermore, the fourth planetary gear stage 98a increases a speed for an impact drive, that is, a speed of the hammer mechanism shaft 54a or of the drive rotation element 52a is higher than a speed of the tool spindle 18a. Thus, the gear arrangement 14a, more precisely the gear stage element 132a, provides different speeds for an impact drive and a rotary drive.

The handheld power tool 10a has a first releasable coupling device 148a which transmits a rotary movement during a percussion drilling operation. The first coupling device 148a is designed as a claw coupling and remains closed in the event of an axial movement of the tool spindle 18a caused by an impact. In a hammer drilling operation, the first coupling device 148a connects the hammer mechanism 16a to the sun gear 114a of the fourth planetary gear stage 98a.

Furthermore, the first coupling device 148a has a spring element 150a which is designed as a spiral spring. The spring element 150a opens the first coupling device 148a when the tool spindle 18a is relieved against the main working direction 26a. In this case, the hammer mechanism 16a is deactivated. The first coupling device 148a is closed by a force transmitted in the axial direction via the tool spindle 18a and emanating from the insert tool 32a during a percussion drilling operation. When the tool spindle 18a is loaded with a force by a force generated by the operator on a workpiece not shown in detail via an insert tool 32a fastened in the tool fastening device 30a, the spring element 150a is compressed and the first coupling device 148a is closed. During a hammer drilling operation, the force is applied in the axial direction to the hammer mechanism shaft 54a and thus to the first coupling device 148a via a shaped element 152a, which is connected to the tool spindle 18a.

In addition, the handheld power tool 10a has the operating element 40a, by means of which the operator can actuate the first coupling device 148a by permanently opening the first coupling device 148a. The hammer mechanism 16a is thus deactivated in this operating state. This operating element 40a thus enables a manual change between a drilling or screwdriving operation and a hammer drilling operation, and it is possible to drill and screw with the hand-held power tool 10a without an impact pulse. The operating element 40a is designed as a slide switch.
The torque setting unit 12a has a coupling device 154a which limits a torque that can be transmitted. A maximum torque is by means of the torque setting unit 12a adjustable. This further, second coupling device 154a is arranged between the ring gear 104a of the third planetary gear stage 96a and the ring gear 106a of the fourth planetary gear stage 98a. The second coupling device 154a opens automatically from an adjustable maximum torque that acts on the tool spindle 18a. If the second clutch device 154a is open, the ring gear 104a of the third planetary gear stage 96a is axially secured and rotatably movable. The second clutch device 154a is designed as an overload clutch known to those skilled in the art, the response torque of which can be changed by an axial force on the second clutch device 154a. For example, the second coupling device 154a is designed as a molded element coupling with inclined surfaces or as a friction coupling. Alternatively, the ring gear 106a of the fourth planetary gear stage 98a serves as a shaped element in that it simultaneously meshes with the planetary gears 128a, 130a of the third planetary gear stage 96a and the fourth planetary gear stage 98a and is shifted in the main working direction 26a when the maximum torque is exceeded and the planet gears 128a of the third planetary gear stage 96a releases. For this purpose, the ring gear 106a of the fourth planetary gear stage 98a is preferably wider than the planetary gears 128a, 130a of the third and / or the fourth planetary gear stage 96a, 98a.

The handheld power tool 10a has a spring element 156a which, during a work process, exerts a force on the axially movable ring gear 106a of the fourth planetary gear stage 98a and thus on the second clutch device 154a and thus closes the second clutch device 154a. By means of the operating element 36a of the torque setting unit 12a, the second clutch device 154a can be adjusted by the operator, that is to say a force can be set on the axially movable ring gear 106a. This is done by an axial movement of a stop point 158a of the spring element 156a. If the maximum torque of the tool spindle 18a is exceeded and the coupling device 154a is not permanently closed manually, the second coupling device 154a brings about a counterforce and compresses the spring element 156a and the coupling device 154a opens. The operating element 36a of the torque setting unit 12a is designed as a ring that can be rotated by the operator.

Furthermore, the operating element 36a has a shaped element (not shown in more detail) which is provided to manually close the second coupling device 154a permanently. This is done by the operator setting the operating element 36a accordingly. As a result, opening of the second coupling device 154a during a drilling operation can be prevented for all torques transmitted via the tool spindle 18a which do not exceed a safety torque.

The gear arrangement 14a has two bearing elements 160a, 162a which radially support the tool spindle 18a. The first bearing element 160a is arranged on the side of the tool spindle 18a facing the tool fastening device 30a. The first bearing element 160a is axially fixedly connected to the tool spindle 18a and is mounted axially displaceably in the handheld power tool housing 22a. Alternatively, the first bearing element can also be axially fixedly connected to the handheld power tool housing and can be axially displaceably mounted on the tool spindle. On the side of the tool spindle 18a facing away from the tool fastening device 30a, the second bearing element 162a is arranged, which supports the tool spindle 18a within the sun gear 114a of the fourth planetary gear stage 98a. Alternatively, the tool spindle 18a can be mounted by means of the common planetary gear carrier 120a, 122a of the third and fourth planetary gear stages 96a, 98a.

In the Figure 6 a further embodiment of the invention is shown. To distinguish the exemplary embodiments, the letter a is in the reference numerals of the exemplary embodiment in FIG Figures 1 to 5 by the letter b in the reference numerals of the embodiment in FIG Figure 6 replaced. The following description is essentially limited to the differences from the exemplary embodiment in FIG Figures 1 to 5 , with regard to components, features and functions that remain the same, refer to the description of the exemplary embodiment in FIGS Figures 1 to 5 can be referenced. In particular, various arrangements and combinations of the coupling device described are conceivable.

Figure 6 shows how Figure 2 in particular a torque setting unit 12b, a gear arrangement 14b, a hammer mechanism 16b and a tool spindle 18b.

The torque setting unit 12b has latching elements 164b which are designed as balls. The latching elements 164b are mounted in shaped elements (not shown in more detail) and are arranged between a ring gear 104b of a third planetary gear stage 96b and a handheld power tool housing 22b. The latching elements 164b are spring-loaded by a spring element 156b of the torque setting unit 12b with a force that can be adjusted by the operator, radially to an axis of rotation 34b of the tool spindle 18b. If a torque transmitted via the tool spindle 18b exceeds a set maximum torque, the latching elements 164b press the shaped elements apart against a force of the spring element 156b. The ring gear 104b of the third planetary gear stage 96b thus rotates relative to the handheld power tool housing 22b and the tool spindle 18b does not transmit any torque at this point in time.

The ring gear 104b of the third planetary gear stage 96b and a ring gear 106b of a fourth planetary gear stage 98b are non-rotatably connected to one another by means of a coupling device 148b. If the coupling device 148b is open, the ring gear 106b of the fourth planetary gear stage 98b is freely rotatable about the axis of rotation 34b and thus the hammer mechanism 16b is switched off for a drilling and screwing operation.

The coupling device 148b is closed by means of two shaped elements 152b, 168b. The first shaped element 152b transmits a force in the axial direction from the tool spindle 18b to a hammer mechanism shaft 54b. This shaped element 152b is axially mechanically fixed to the tool spindle 18b.

The second shaped element 166b is connected to the hammer mechanism shaft 54b in the axial direction. It transmits the force in the axial direction via a bearing 168b to the ring gear 106b of the fourth planetary gear stage 98b. The force closes the coupling device 148b during a drilling and screwing operation. Alternatively, the power can be transmitted via the fourth planetary gear stage 98b possible. The coupling device 148b is opened by a spring element 150b which, via a bearing 170b, applies an axial force that is aligned with a tool fastening device 30b to the hammer mechanism shaft 54b.

Claims (16)

1. Portable power tool, in particular hammer drill driver, having a transmission arrangement (14; 14b), a hammer percussion mechanism (16a; 16b) and a tool spindle (18a; 18b), wherein the hammer percussion mechanism (16a; 16b) has a linearly moved striker (68a; 68b) with a linear percussive pulse direction, which at least partially encloses the tool spindle (18a; 18b) in at least one plane, wherein the tool spindle (18b; 18b), for transmitting rotational forces, has a rotary driving contour (140a) that is intended to establish an axially displaceable and rotationally fixed connection along an axis of rotation (34a; 34b), characterized in that the tool spindle (18a; 18b) is formed in a two-part manner and the rotary driving contour (140a) divides the tool spindle (18a; 18b) axially into two parts (142a, 144a).
2. Portable power tool according to Claim 1, characterized in that the striker (68a; 68b) strikes the tool spindle (18a; 18b) in at least one operating state.
3. Portable power tool according to Claim 1 or 2, characterized in that the hammer percussion mechanism (16a; 16b) has a spring-elastic lever element (66a; 66b) that is mounted so as to be pivotable about a pivot axis and is intended to drive the striker (68a; 68b) of the hammer percussion mechanism (16a; 16b) in at least one operating state.
4. Portable power tool according to one of the preceding claims, characterized in that the striker (68; 68b) is freely movable in a main working direction (26a; 26b) in at least one operating state.
5. Portable power tool according to one of the preceding claims, characterized in that the transmission arrangement (14a; 14b) has at least one sun gear (114a; 114b) that is connected to at least one part of the hammer percussion mechanism (16a; 16b) for conjoint rotation in at least one operating state.
6. Portable power tool according to one of the preceding claims, characterized by an electric motor (24a; 24b) and a rechargeable-battery connection unit (20a; 20b) that is intended to supply the electric motor (24a; 24b) with energy.
7. Portable power tool according to one of the preceding claims, characterized in that the hammer percussion mechanism (16a; 16b) has a releasable clutch device (148a; 148b) that is intended to transmit a rotary movement.
8. Portable power tool according to Claim 7, characterized in that the clutch device (148a; 148b) is intended to be closed by a force transmitted via the tool spindle (18a; 18b).
9. Portable power tool according to one of the preceding claims, characterized by a torque setting unit (12a; 12b) that has a clutch device (154a; 154b) that is intended to limit a maximum torque transmitted via the tool spindle (18a; 18b) in at least one operating state.
10. Portable power tool at least according to Claim 7 and/or 9, characterized by a control element (36a, 40a; 36b, 40b), by means of which the clutch device (148a, 154a; 148b, 154b) can be actuated.
11. Portable power tool according to one of the preceding claims, characterized in that the hammer percussion mechanism (16a; 16b) has a drive rotation element (52a; 52b) with an axis of rotation (34a; 34b) that is arranged coaxially with at least one part of the tool spindle (18a; 18b).
12. Portable power tool according to Claim 11, characterized in that the drive rotation element (52a; 52b) is in the form of a percussion mechanism shaft (54a; 54b) that encloses at least one region of the tool spindle (18a; 18b).
13. Portable power tool according to one of the preceding claims, characterized in that the transmission arrangement (14a; 14b) has at least one transmission stage element (132a; 132b) that is intended to divide a force flux in order to provide different speeds for percussion operation and rotary operation.
14. Portable power tool according to one of the preceding claims, characterized in that the transmission arrangement (14a; 14b) has at least one ring gear (106a; 106b) that is mounted in an axially movable manner.
15. Portable power tool according to one of the preceding claims, characterized in that the transmission arrangement (14a; 14b) has at least one transmission stage (98a; 98b) that is intended to increase a speed for percussion operation.
16. Portable power tool according to one of the preceding claims, characterized in that the tool spindle (18b; 18b) has a further rotary driving contour (134a; 134b), which is intended to establish an axially displaceable and rotationally fixed connection to the transmission arrangement (14a; 14b) along an axis of rotation (34a; 34b).

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