EP2448717B1 - Hand-held power tool - Google Patents

Description

State of the art

The invention relates to a hand tool according to the preamble of claim 1.

Such a hand tool machine is from the EP1 690 642 A1 known.

It has already been proposed a hand tool, in particular a Schraubbohrhammer, with a gear assembly, a hammer blower and a tool spindle.

Disclosure of the invention

The invention relates to a hand tool, in particular a Schraubbohrhammer, with a gear assembly, a hammer blower and a tool spindle.

It is proposed that the hammer impact mechanism has a racket which at least partially surrounds the tool spindle in at least one plane. A "gear arrangement" is to be understood to mean an arrangement which has at least one gear stage. Advantageously, the gear stage is designed as a bevel gear, as a bevel gear and / or as another, the expert appears appropriate gear stage. Particularly advantageously, the gear stage is designed as a planetary gear stage. A "hammer impact mechanism" should be understood to mean a striking mechanism with at least one linearly moved racket. Advantageously, the hammer blower moves the bat resiliently and / or pneumatically and / or hydraulically by means of a link device, by means of a swash bearing and / or advantageously by means of an eccentric element. Thus, the hammer mechanism is preferably designed as a sliding block, as a swash bearing impactor and / or as an eccentric percussion. A "sliding impact mechanism" is to be understood in particular as a hammer impact mechanism with a slide mechanism. A linkage device generates a linear movement between at least two areas by elements that are movable on a mechanically limited endless track. In particular, a "swash bearing impactor" is to be understood as meaning a bearing with a finger which is connected to a drive rotary element of the hammer impact mechanism and whose bearing plane deviates from a plane which is oriented perpendicular to the axis of rotation of the drive rotary element. An "eccentric striking mechanism" is to be understood in particular as meaning a hammer impact mechanism which is intended to generate a linear movement perpendicular to the axis of rotation of the rotational movement from a rotational movement. Preferably, the eccentric percussion on an eccentric element which is rotatably connected to the drive rotary member. A "hammer impact mechanism" should not be understood as a detent impact mechanism in which a rotatable detent disk is permanently mechanically mechanically fixed to the hand tool housing and in which the detent disk interacts with a detent disk mechanically mechanically connected to the tool spindle: a detent impactor is in particular a striking mechanism in which a punch-generating detent disc is driven in rotation. An axial toothing of the detent disc causes an axial movement of the tool spindle. A "tool spindle" is to be understood as meaning a shaft of the handheld power tool which, in at least one operating state, transmits a rotational movement to a tool fastening device of the handheld power tool. Preferably, a rotation axis of the tool spindle lies on a rotation axis of an insertion tool and / or the tool fastening device. Particularly advantageously, the tool spindle transmits a rotational movement and a striking movement to the tool fastening device in at least one operating state. Particularly advantageously, at least part of the tool spindle is connected directly to the tool fastening device. The tool spindle preferably has a fastening for the tool fastening device. AIternativ the tool spindle may be at least partially formed integrally with the tool fastening device. The tool fastening device is advantageously designed as a tool chuck, as a hexagonal mount, as an SDS mount (special direct system from Robert Bosch GmbH) and / or as another tool fastener that appears expedient to the person skilled in the art. "Provided" is to be understood in particular to be specially equipped and / or designed. The tool spindle advantageously passes at least partially through the racket in the direction of the axis of rotation of the tool spindle. The spindle passes completely through the racket whereby racket encloses the tool spindle in at least one plane by 360 °

The inventive design of the power tool can advantageously a tool spindle can be achieved with a low mass and thus a particularly lightweight and compact hand tool with high performance can be provided.

In an advantageous embodiment of the invention, it is proposed that the racket strike the tool spindle in at least one operating state. Advantageously, the racket transmits a shock pulse to at least a portion of the tool spindle, wherein the tool spindle advantageously transmits the impact pulse to a tool fastening device of the power tool. The tool attachment device preferably transmits the impact pulse to an insert tool. Alternatively and / or additionally, the racket strikes a shock transmission device, such as an anvil, or directly on an insert tool of the power tool. The impact transmission device transmits a striking motion directly to an insert tool. For this purpose, the impact transmission device is arranged, for example, at least partially coaxially within the tool spindle. By virtue of the racket striking the tool spindle, the tool spindle can advantageously combine a striking movement and a rotary movement to be transferred to a tool fastening device, thereby advantageously producing an inexpensive, universally applicable one and structurally simple tool fastening device used and again space can be saved.

In a further embodiment, it is proposed that the hammer impact mechanism has a spring-elastic, about a pivot axis pivotally mounted lever member which is intended to drive the racket of the hammer percussion in at least one operating condition. A "lever element" is to be understood in particular a movable element, act on the at least two torques at a distance, advantageously at a different distance to the pivot axis. Preferably, the lever element is pivotable about a pivot axis which is aligned perpendicular to the axis of rotation of the tool spindle. Particularly advantageously, the lever element is configured rotationally asymmetric and / or can be moved about an axis of rotation by less than 360 °. The term "elastic" is to be understood in particular that at least one point of the lever member is deflected relative to another point of the lever member during an operating state by at least 1 mm. Advantageously, the lever element is at least partially made of spring steel. The term "drive" should be understood to mean, in particular, accelerating. <br/> <br/> The lever element can be used to constructively realize an effective and cost-effective hammer impact mechanism.

In an advantageous embodiment of the invention it is proposed that the racket is freely movable in at least one operating state in a main working direction. Preferably, the racket is movable by the lever element. By "freely movable" is to be understood in this context, in particular, that the racket over at least a distance in the main working direction of components, with the exception of a sliding and / or rolling friction in a guide, is decoupled. In particular, a "main working direction" should be understood to mean a direction of impact of the hammer impact mechanism. By in at least one operating state freely movable racket a particularly large impact energy and thereby a comfortable and low-vibration operation can be achieved.

It is also proposed that the tool spindle has a rotational engagement contour which is provided to be axially displaceable along an axis of rotation and establish rotatable connection. In this case, the rotary driving contour advantageously transmits primarily, particularly advantageously exclusively, rotational forces. The rotational engagement contour is designed as a rotational engagement contour that appears appropriate to the person skilled in the art, such as, in particular, a splined shaft profile and / or advantageously like a gearing. Particularly advantageously, the tool spindle is formed in two parts and the rotary driving contour connects the two parts of the tool spindle with each other. Due to the rotational engagement contour, a ratio between racket and spindle mass can advantageously be optimally selected and the tool spindle can be decoupled axially from the gear arrangement, as a result of which wear, in particular on a planet 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-rotatable, in particular directly, i.e. without intermediary further components, rotatably connected to at least a portion of the hammer impact mechanism, whereby a structurally particularly simple and space-saving design is possible. Advantageously, the sun gear is rotatably connected to a drive rotary element of the hammer impact mechanism.

Further, an electric motor and a Akkuanschlusseinheit proposed, which is intended to provide the electric motor with energy. For this purpose, the battery connecting unit is preferably connected to a battery unit in an operational state of operation. A "battery connection unit" should be understood in particular to mean a unit which is intended to make contact with the battery unit. Advantageously, the Akkuanschlusseinheit produces an electrical and a mechanical contact. A "rechargeable battery unit" is to be understood in particular as a device having at least one rechargeable battery, which is intended to supply the portable power tool with power independently of the mains. As a result, a particularly convenient and usable independently of a power supply hand tool is feasible. Alternatively, the hand tool can also be operated with another motor that appears appropriate to a person skilled in the art, such as, in particular, an electric motor having a mains connection or a compressed-air motor.

In addition, it is proposed that the gear arrangement has 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 planetary gear and / or a planet carrier. Due to the planetary gear stage can be achieved in a particularly space-saving advantageous reduction.

Furthermore, it is proposed that the hammer impact mechanism has a releasable, in particular mechanically releasable coupling device, which is intended to transmit a rotational movement. Preferably, in at least one operating state, the coupling device rotatably connects a striking mechanism shaft of the hammer impact mechanism and at least a part of the transmission assembly. A "releasable coupling device" is to be understood in particular a coupling device which transmits a rotational movement in at least one operating state and which interrupts transmission of the rotational movement in at least one operating state. Under "transmit a rotary motion" is to be understood in particular a speed and / or torque forward. Due to the releasable coupling device, the hammer impact mechanism can advantageously be switched off, and thus an advantageously usable as a screwdriver hand tool can be achieved.

It is also proposed that the coupling device is intended to be closed by a force transmitted via the tool spindle. Preferably, the coupling device is provided to be closed by a force acting in the axial direction of the tool spindle force. By closable via the tool spindle coupling device advantageously the hammer impact mechanism can be automatically switched on during a drilling operation and switched off at idle, which allows low wear and ease of use.

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

Furthermore, it is proposed that the handheld power tool has an operating element by means of which the coupling device can be actuated. Advantageously, at least the operator can actuate 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 actuating unit can actuate the coupling device at least partially automatically based on material properties of a workpiece. Preferably, the coupling device of the torque adjusting unit and the coupling device of the hammer impact mechanism each have one and / or a common operating element. By "actuate" should be understood in particular open and / or close the coupling device, whereby the impact operation can be switched on and off comfortably by the operator and in particular the coupling device of Drehmomenteinstelleinheit can be permanently closed in a drilling operation.

The hammer impact mechanism has a drive rotation element with a rotation axis, which is arranged coaxially to at least a part of the tool spindle. A "drive rotation element" is to be understood as an element which, in at least one operating state, carries out a rotational movement and which moves at least one further element of the hammer impact mechanism. Advantageously, the drive rotation element is designed as a shaft, particularly advantageously as a hollow shaft. The term "coaxial" is to be understood that at least a part of the tool spindle and the drive rotation element are driven in rotation in at least one operating state about a common axis of rotation.

Preferably, at least a part of the tool spindle and the drive rotation element are rotatable about the same axis of rotation relative to each other. Particularly advantageously, the power tool is formed undulating. By "inter-shaft" is to be understood in particular that all waves of the power tool, which transmit rotational movement at least in a drilling operation, have a common axis of rotation, which advantageously coincide with the axis of rotation of the tool spindle. By "at least a portion of the tool spindle" is meant in particular a region of the tool spindle, which is connected directly to the tool fastening device. Alternatively and / or additionally, "at least a part of the tool spindle" is to be understood as meaning a region of the tool spindle which is connected directly to the gear arrangement. By the coaxial with at least a portion of the tool spindle arranged drive rotational element, a particularly compact and particularly short design can be achieved. In this case, the power tool achieves a particularly high single impact energy, which advantageously leads to a particularly good drilling progress.

In a further embodiment, it is proposed that the drive rotary element is designed as a striking mechanism shaft, which surrounds at least a portion of the tool spindle. A "percussion shaft" is to be understood as meaning a shaft which transmits a rotational movement to at least one further element of the hammer impact mechanism for generating a shock. Particularly advantageously, the tool spindle and the percussion shaft rotate in at least one operating state with a different angular velocity. The term "envelop" is to be understood in particular that the percussion shaft, the tool spindle in at least one plane for the most part, advantageously encloses 360 °. Advantageously, this plane is oriented perpendicular to the axis of rotation of the drive rotation element. By a corresponding configuration, a particularly space-saving design can be achieved and the impactor shaft enclosing the tool spindle can be realized with a low tool spindle mass and a small tool spindle diameter.

It is also proposed that the hammer impact mechanism has an eccentric element, whereby structurally simple a mechanically low-wear and a powerful hand tool can be provided.

In addition, it is proposed that the eccentric element has an axis of rotation which coincides with an axis of rotation of the tool spindle. The term "coincide" is to be understood in particular that the eccentric element is mounted for rotation about a same axis of rotation as the tool spindle. Preferably, the eccentric element and at least a portion of the tool spindle are rotatably connected to each other. This can advantageously be dispensed with an intermediate shaft and it can be a particularly handy and lightweight hand tool can be achieved. In particular, a powerful hand tool with a weight including a battery less than 5kg, advantageously less than 2kg, particularly advantageously less than 1.5kg can be achieved.

In addition, it is proposed that the gear arrangement has at least one gear step element, which is provided to divide a power flow in order to provide different rotational speeds for a percussion drive and a rotary drive. A "gear step element" is to be understood in particular as meaning a sun gear, a ring gear, a planet wheel, another element of the gear arrangement which appears appropriate to the person skilled in the art, and / or in particular a planet gear carrier. By "split" is to be understood in this context, in particular, that act on the gear stage element at least three places forces that cause torques, 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 for a particularly effective rate of impact and thus a particularly large rate of drilling progress can be achieved in a percussion drilling operation.

It is also proposed that the gear arrangement generates at least two output rotary movements in at least one operating state, which have an odd-numbered relationship to one another. Preferably, in at least one operating condition, the gear assembly transmits one of the output rotational motions to the tool spindle and one of the output rotational motions on the hammer blower. An "odd-numbered relationship" should be understood in particular as meaning a ratio that lies outside a natural set of numbers. Preferably, the ratio is outside the natural number of numbers between 2 and 6. By "initial rotational movement" should be understood in particular a rotational movement, which leads a power out of the gear assembly out. Due to the ungranted ratio between the two output rotational movements, an advantageous impact pattern can be achieved, which enables a particularly effective percussion drilling operation.

In a further embodiment, it is proposed that the gear arrangement has at least one ring gear, which is mounted axially movable. By "axially movably mounted" should be understood to be movable in particular in a direction parallel to a rotational axis of the ring gear. Advantageously, the ring gear relative to a hand tool housing, compared with at least one planetary gear of the same gear stage and / or against at least one planetary gear of another gear stage movable. Particularly advantageously, the ring gear is movable so that it is coupled with at least one planetary gear two different gear stages simultaneously and / or successively. Due to the axially movably mounted ring gear structurally simple and cost-effective a Überrastkupplung and / or a blowout can be realized.

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

It is also proposed; that the gear arrangement has at least one gear stage, which is intended to increase a rotational speed for a percussion drive, whereby an advantageously high impact rate and thus an effective impact drilling operation can be achieved.

drawing

Further advantages emerge from the following description of the drawing. In the drawings, two embodiments of the invention are shown. 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 hand tool according to the invention with a drive train, shown schematically,

Fig. 2

a functional sketch of the drive train FIG. 1 with an electric motor, a gear arrangement and a hammer impact mechanism,

Fig. 3

a schematic partial section through the hammer mechanism of the power tool FIG. 1 .

Fig. 4

a cut through the hammer blower FIG. 3 .

Fig. 5

a lever element of the hammer impact mechanism FIG. 3 in a perspective view and

Fig. 6

a functional diagram of an alternative embodiment of the drive train from FIG. 1 ,

Description of the embodiments

FIG. 1 shows a hand tool 10a, which is designed as a cordless combi drill, in a partially schematic representation. The hand tool 10a has a Drehmomenteinstelleinheit 12a, a gear assembly 14a, a hammer mechanism 16a, a tool spindle 18a, a Akkuanschlusseinheit 20a, a pistol-shaped portable power tool housing 22a and a arranged in the power tool housing 22a electric motor 24a. In a contrary to a main working direction 26a of the handheld power tool 10a seen in the front portion 28a of the power tool 10a, the power tool 10a has a tool attachment device 30a, which is designed as a tool chuck. Mounted in the tool attachment device 30a is an insert tool 32a which, during operation of the hand tool 10a, rotates about an axis of rotation 34a of the tool spindle 18a that extends parallel to the main working direction 26a. The rotation axis 34a is formed as a main rotation axis, that is, a plurality of elements of the power tool 10a are rotatable about this rotation axis 34a.

An operating element 36a of the torque setting unit 12a is arranged in an annular manner about the rotation axis 34a of the tool spindle 18a, between the hand-held power tool housing 22a and the tool fastening device 30a. On an upper side, that is to say one of the battery terminal unit 20a facing away from side 38a of the power tool 10a, a control element 40a is arranged, which allows an operator not shown a change between a drilling or screwing operation and a percussion drilling operation.

In a rear, that is the tool fastening device 30a remote from region 42a of the power tool housing 22a, the electric motor 24a is arranged. A not-shown stator of the electric motor 24a is rotatably connected to the power tool housing 22a. In a tubular, upper region 44a of the pistol-shaped hand-held power tool housing 22a arranged axially to the rotation axis 34a, the gear arrangement 14a is arranged. A lower portion 46a of the power tool housing 22a, which connects approximately at right angles to the upper portion 44a, forms a handle 48a. At a lower end of the lower portion 46a, the battery terminal unit 20a is disposed. To the battery terminal unit 20a, a battery unit 50a is connected in an operating state shown. The battery unit 50a supplies the electric motor 24a with power during operation.

As the Figures 2 and 3 show, the hammer mechanism 16a a drive rotary member 52a with a rotation axis 34a, which is coaxial with the tool spindle 18a is arranged. The drive rotation member 52a is formed as a hammer shaft 54a. The percussion shaft 54a encloses a portion of the tool spindle 18a, which faces the gear assembly 14a. The axis of rotation 34a of the impactor shaft 54a is aligned parallel to the main working direction 26a of the hand tool 10a. The tool spindle 18a rotatably connects the tool attachment device 30a to the gear assembly 14a along the rotation axis 34a, and is largely formed as a solid shaft.

The hammer mechanism 16a is formed as an eccentric impactor having an eccentric 56a. In again FIG. 4 shown section (AA), the eccentric 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, whose wall thickness 58a increases and decreases continuously in the course of 360 ° about the axis of rotation 34a. The eccentric 56a is rotatably connected to the percussion shaft 54a and is penetrated by this in the axial direction. Hammer impactor 16a has an eccentric outer member 60a that is moved by eccentric member 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 remote from the handle 48a region 64a of the eccentric outer element 60a. In the bore 62a, the eccentric element 56a is mounted movably 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 member 66a prevents rotation of the eccentric outer member 60a in the circumferential direction relative to the power tool housing 22a.

The hammer mechanism 16a has a racket 68a. The lever member 66a drives the racket 68a during a percussion drilling operation. The lever member 66a is formed as a, in a side view, L-shaped bracket made of spring steel. As FIG. 5 shows, the lever member 66a a horseshoe-shaped portion 70a, which is penetrated by the tool spindle 18a. The Hammer impact mechanism 16a has a housing-fixed pivot axis 72a, about which the lever member 66a is tiltable. The housing-fixed pivot axis 72a is aligned perpendicular to the rotational axis 34a of the tool spindle 18a.

Furthermore, the show Figures 2 and 3 in that the beater 68a of the hammer impact mechanism 16a is freely movable during a free-flying phase in the main working direction 26a. The free-flying phase is a period beginning with an end of acceleration of the beater 68a by the lever member 66a and ending immediately before a bounce. In a shock, the beater 68a transmits a shock pulse to the tool spindle 18a. For this purpose, the racket 68a strikes a transmission element 74a of the tool spindle 18a. The transmission element 74a is formed as a thickening of the tool spindle 18a, which has a surface 76a on a side facing the racket 68a. The surface 76a is aligned parallel to a striking surface 78a of the racket 68a. The racket 68a encloses the tool spindle 18a in planes aligned perpendicular to the axis of rotation 34a of the tool spindle 18a by 360 °. The racket 68a is guided on the tool spindle 18a and is mounted rotatably about the rotation axis 34a of the tool spindle 18a relative to the hand tool housing 22a. Alternatively, the racket can also be guided on its outer contour and / or rotationally secured relative to the hand tool housing.

Upon rotation of the eccentric 56a, the eccentric outer 60a moves perpendicular to the axis of rotation 34a of the tool spindle 18a. By a movement of the eccentric outer element 60a, an end 82a of the lever element 66a which is tiltably arranged in the opening 80a of the eccentric outer element 60a is moved and thereby the lever element 66a is tilted. 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 acceleration, the striker 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 region 88a of the striker 68a and thus decoupled from the striker 68a in the main working direction 26a. At the end of this free flight phase, the racket 68a hits on the transmission element 74a of the tool spindle 18a and transmits its pulse to the tool spindle 18a. Then, the lever member 66a returns the racket 68a to the home position by the driving end 84a of the lever member 66a exerting a force on a second support surface 90a of the rack 68a disposed on another side of the free area 88a with respect to the first support surface 86a. Due to the resilient design of the lever member 66a jump-free courses of the forces acting between the lever member 66a and the racket 68a, achieved.

The gear assembly 14a has four gear stages, which are formed 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 rotational axis 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 carrier 116a, 118a, 120a, 122a and four planetary 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 supported on the planet carrier 116a of the first planetary gear stage 92a. The planet carrier 116a of the first planetary gear stage 92a guides the planetary gears 124a of the first planetary gear stage 92a in a circular path about the rotation axis 34a of the tool spindle 18a. The second planetary gear 94a, the third planetary gear 96a and the fourth planetary gear 98a are constructed accordingly.

The sun gear 108a of the first planetary gear stage 92a is rotatably connected to the electric motor 24a and disposed in the main operating direction 26a adjacent to the electric motor 24a, between the tool mounting device 30a and the electric motor 24a. The ring gear 100a of the first planetary gear stage 92a is rotatably connected to the 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 94a, the ring gear 102a is also connected to the power tool housing 22a. The planet carrier 118a of the second planetary gear stage 94a is rotatably connected to the sun gear 112a of the third planetary gear stage 96a. The ring gear 104a of the third planetary gear stage 96a is also rotatably connected to the power tool housing 22a during a drilling, screwing or hammering operation. Thus, the first, second and third planetary gear stages 92a, 94a, 96a each cause a reduction in the direction of the tool attachment device 30a. There is thus also a reduction between the sun gear 108a of the first planetary gear stage 92a and the planet carrier 120a of the third planetary gear stage 96a. A ratio of this reduction between a rotational speed of the electric motor 24a and a rotational speed of the tool spindle 18a is approximately 60: 1.

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

The gear assembly 14a includes a gear stage member 132a that divides a power flow. The gear stage member 132a is formed as a common planet carrier 120a, 122a of the third and fourth planetary gear stages 96a, 98a. The tool spindle 18a has a rotational engagement 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 rotational axis 34a. Accordingly, a tapping of a rotational speed of the tool spindle 18a takes place on the planet carrier 120a of the third planetary gear stage 96a.

In this example, the rotational engagement contour 134a is as an internal toothing 136a of the gear stage member 132a and an outer toothing 138a of Tool spindle 18a formed. Alternatively, the tap could be made on the ring gear of the third planetary gear stage 96a.

Alternatively or in addition to the in FIG. 2 As shown in FIG. 1 and described above, the rotational engagement contour 134a may be as shown in FIG FIG. 3 A rotary drive contour 140a axially divides the tool spindle 18a into two parts 142a, 144a. The one part 142a of the tool spindle 18a is directly connected to the gear assembly 14a. The other part 144a of the tool spindle 18a is directly connected to the tool attachment device 30a. The rotational drive contour 134a described above can be dispensed with. The portion 142a of the tool spindle 18a, which is directly connected to the gear assembly 14a, may then be fixedly connected in the axial direction with the gear stage member 132a. Thereby, 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 rotatably connected to the drive rotation member 52a during a percussion drilling operation. Thus, the sun gear 114a of the fourth planetary gear stage 98a is rotatably connected to the eccentric element 56a of the hammer impact mechanism 16a during a percussion drilling operation. Alternatively, the ring gear 106a of the fourth planetary gear stage 98a could also be connected in a rotationally fixed manner to the drive rotation element 52a.

The ring gear 106a of the fourth planetary gear stage 98a is mounted axially movable. 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 train 14a, more specifically, the fourth planetary gear train 98a, generates output rotational motions having an odd-numbered relationship with each other during a percussion drilling operation from the two power fluxes of the common carrier 120a, 122a of the third and fourth planetary gears 96a, 98a. Further, the fourth planetary gear stage 98a increases a rotational speed for a percussion drive, that is, a rotational speed of the percussion shaft 54a and the drive rotational element 52a is higher than a rotational speed of the tool spindle 18a. Thus, the gearbox provides 14a, more precisely the gear stage element 132a, different speeds for a percussion and a rotary drive ready.

The hand tool 10a has a first releasable coupling device 148a, which transmits a rotational movement during a percussion drilling operation. The first coupling device 148a is formed as a dog clutch and remains closed during an axial movement of the tool spindle 18a caused by a shock. In a percussion drilling operation, the first coupling device 148a connects the hammer hammer 16a to the sun gear 114a of the fourth planetary gear set 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 through the tool spindle 18a in the axial direction, by the insert tool 32a, during a percussion drilling operation. When the tool spindle 18a is loaded with force by a force generated by the operator on a workpiece, not shown, via an insert tool 32a fastened in the tool attachment device 30a, the spring element 150a is compressed and the first coupling device 148a is closed. The force is applied in the axial direction in a percussion drilling operation via a shaping element 152a, which is connected to the tool spindle 18a, on the striking mechanism shaft 54a and thus on the first coupling device 148a.

In addition, the hand 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. Thus, the hammer blower 16a is deactivated in this operating state. Thus, this operating element 40a allows a manual change between a drilling or screwing operation and a percussion drilling operation and it can be drilled and screwed with the hand tool 10a without impact pulse. The operating element 40a is designed as a slide switch.

The torque adjusting unit 12a has a coupling device 154a that limits a transmittable torque. A maximum torque is adjustable by means of Drehmomenteinstelleinheit 12a. 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 clutch device 154a opens automatically from an adjustable maximum torque acting on the tool spindle 18a. When the second clutch device 154a is opened, the ring gear 104a of the third planetary gear train stage 96a is axially secured and rotatably movable. The second clutch device 154a is designed as an overload clutch known to the person 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 formed as a form element coupling with inclined surfaces or as a friction clutch. Alternatively, the ring gear 106a of the fourth planetary gear stage 98a serves as a form element by simultaneously meshing with the planetary gears 128a, 130a of the third planetary gear stage 96a and the fourth planetary gear stage 98a and displaced when the maximum torque is exceeded in the main working direction 26a 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 planet gears 128a, 130a of the third and / or the fourth planetary gear stage 96a, 98a.

The portable power tool 10a has a spring element 156a, which 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 during operation, thus closing the second clutch device 154a. By means of the operating element 36a of the torque setting unit 12a, the second coupling device 154a can be adjusted by the operator, that is, a force can be set on the axially movable ring gear 106a. This is done by an axial movement of an abutment 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 causes a counterforce and compresses the spring element 156a and the coupling device 154a opens. The operating element 36a of the torque adjusting unit 12a is formed as a ring rotatable by the operator.

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

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

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

FIG. 6 shows how FIG. 2 Specifically, a torque adjusting unit 12b, a gear assembly 14b, a hammer hammer 16b, and a tool spindle 18b.

The Drehmomenteinstelleinheit 12b has locking elements 164b, which are formed as balls. The locking elements 164b are mounted in non-illustrated form elements and are disposed between a ring gear 104b of a third planetary gear stage 96b and a 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 a rotation axis 34b of the tool spindle 18b. If a torque transmitted via the tool spindle 18b exceeds a set maximum torque, the latching elements 164b push the shaped elements apart against a force of the spring element 156b. Thus, the ring gear 104b of the third planetary gear stage 96b rotates relative to the portable power tool housing 22b, and the tool spindle 18b does not transmit torque at this 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. When the coupling device 148b is opened, the ring gear 106b of the fourth planetary gear stage 98b is freely rotatable about the rotation axis 34b and thus the hammer blower 16b is switched off for a drilling and screwing operation.

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

The second mold member 166b is connected to the percussion 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, a transmission of the force across the fourth planetary gear stage 98b possible. The coupling device 148b is opened by a spring element 150b, which applies a axial force aligned with a tool fastening device 30b to the striking mechanism shaft 54b via a bearing 170b.

Claims (15)

1. Hand-held power tool, in particular heavy-duty helical hammer drill, with a gearing arrangement (14a; 14b), a hammer impact mechanism (16a; 16b) and a tool spindle (18a; 18b), wherein the hammer impact mechanism (16a; 16b) has a linearly moving beater (68a; 68b) with a linear impact loading direction, wherein the hammer impact mechanism (16a; 16b) has a driving rotational element (52a; 52b) with an axis of rotation (34a; 34b) which is arranged coaxially with respect to at least part of the tool spindle (18a; 18b), characterized in that the beater at least partially surrounds the tool spindle (18a; 18b) in at least one plane, and in that the driving rotational element (52a; 52b) is designed as an impact mechanism shaft which encases at least a region of the tool spindle (18a; 18b).
2. Hand-held power tool according to Claim 1, characterized in that the beater (68a; 68b) impacts against the tool spindle (18a; 18b) in at least one operating state.
3. Hand-held power tool according to Claim 1 or 2, characterized in that the hammer impact mechanism (16a; 16b) has a spring-elastic lever element (66a; 66b) which is mounted pivotably about a pivot axis and is provided to drive the beater (68a; 68b) of the hammer impact mechanism (16a; 16b) in at least one operating state.
4. Hand-held power tool according to one of the preceding claims, characterized in that the beater (68a; 68b) is freely movable in a main working direction (26a; 26b) in at least one operating state.
5. Hand-held power tool according to one of the preceding claims, characterized in that the tool spindle (18b; 18b) has a rotational carry-along contour (134a, 140a; 134b) which is provided for producing an axially displaceable and non-rotatable connection along an axis of rotation (34a; 34b).
6. Hand-held power tool according to one of the preceding claims, characterized in that the gearing arrangement (14a; 14b) has at least one sun wheel (114a; 114b) which, in at least one operating state, is connected non-rotatably to at least part of the hammer impact mechanism (16a; 16b).
7. Hand-held power tool according to one of the preceding claims, characterized by an electric motor (24a; 24b) and an accumulator connection unit (20a; 20b) which is provided for supplying the electric motor (24a; 24b) with energy.
8. Hand-held power tool according to one of the preceding claims, characterized in that the hammer impact mechanism (16a; 16b) has a releasable coupling device (148a; 148b) which is provided for transmitting a rotational movement.
9. Hand-held power tool according to Claim 8, characterized in that the coupling device (148a; 148b) is provided to be closed by a force transmitted via the tool spindle (18a; 18b).
10. Hand-held power tool according to one of the preceding claims, characterized by a torque-adjusting unit (12a; 12b) which has a coupling device (154a; 154b) which is provided in order, in at least one operating state, to limit a maximum torque transmitted via the tool spindle (18a; 18b).
11. Hand-held power tool at least according to Claim 8 and/or 10, characterized by an operating element (36a, 40a; 36b, 40b) by means of which the coupling device (148a, 154a; 148b, 154b) can be actuated.
12. Hand-held power tool according to one of the preceding claims, characterized in that the gearing arrangement (14a; 14b) has at least one gearing stage element (132a; 132b) which is provided to divide a force flux in order to provide different rotational speeds for an impact drive and a rotational drive.
13. Hand-held power tool according to one of the preceding claims, characterized in that the gearing arrangement (14a; 14b) has at least one ring gear (106a; 106b) which is mounted in an axially movable manner.
14. Hand-held power tool according to one of the preceding claims, characterized in that the gearing arrangement (14a; 14b) has at least one gearing stage (98a; 98b) which is provided to increase a rotational speed for an impact drive.
15. Hand-held power tool according to one of the preceding claims, characterized in that at least part of the tool spindle and the driving rotational element are rotatable relative to each other about the same axis of rotation.

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