Attachment device

Abstract

The invention relates to an attachment device for arrangement on a handheld power tool (12a, 12b), having a tool receptacle (18a; 18b) for receiving a tool insert, and having at least one rotary hammer mechanism (20a; 20b) which, in at least one operating state, is provided for generating a rotary hammer impulse for hammer-action drive of the tool receptacle (18a; 18b). It is proposed that the rotary hammer mechanism (20a; 20b) has at least one planetary gear set (30a; 30b) which is provided for converting a rotational speed and / or a torque of an output shaft (32a; 32b) of the handheld power tool (12a; 12b) into a rotational speed and / or a torque of the tool receptacle (18a; 18b).

Description

State of the art

[0001] From DE 10 2005 048 345 A1, an attachment device for an arrangement on a hand-held machine tool, with a tool holder for receiving an insert tool and with at least one rotary impact mechanism, which in at least one operating state is provided to generate a rotary impact impulse to an impact drive of the tool holder, is already known.

[0002] EP 2 338 644 A2 discloses a hand tool handle for selectable connection with a hand tool head.

[0003] DE 10 2015 201921 A1 discloses an accessory device for an arrangement on a hand-held machine tool, which includes a ratchet impact unit.

[0004] DE 20 2013 008724 U1 describes a tool attachment for a hand-held power tool with a handle, comprising an attachment housing, wherein an additional handle is permanently or detachably attached to the attachment housing.

[0005] From EP 3 081 341 A1 a tool attachment for a hand-held machine tool is known, wherein a percussion mechanism is arranged in an attachment housing and a tool holder of the hand-held machine tool is fixed in position in the attachment housing, at least during percussion operation. Disclosure of the invention Revised description page 1a - Final version

[0006] The invention relates to an attachment device according to claim 1 for an arrangement on a hand-held power tool, with a tool holder for receiving an insert tool and with at least one rotary impact mechanism which in at least one operating state is provided to generate a rotary impact impulse to a percussive drive of the tool holder.

[0007] It is proposed that the rotary impact mechanism shall have at least one planetary gear designed to translate a rotational speed and / or torque of an output shaft of the hand-held power tool into a rotational speed and / or torque of the tool holder.

[0008] In this context, an "attachment device" is understood to mean, in particular, a device designed for operation with a base device that includes a drive unit for a rotary drive. Preferably, the attachment device is designed for a specific application. Preferably, the attachment device is designed exclusively for operation with a base device, especially a hand-held power tool. Preferably, the attachment device is interchangeable with other attachment devices with the same or a different application. Particularly preferably, the base device can be operated independently of the attachment device.The term "handheld power tool" refers in particular to a power tool that can be held in the hand by an operator, but preferably to a cordless screwdriver, a drill, a rotary and / or impact hammer, a milling machine, a grinder, and / or a multi-tool. Preferably, the handheld power tool has a drive unit for a rotary drive, more preferably an electric drive unit, for example, an electric motor. Preferably, the handheld power tool can be operated independently of a mains power supply. Preferably, the handheld power tool can be connected to an energy storage device, for example, a battery pack. The term "tool holder" refers in particular to a component designed to receive a machining tool in a receiving area and to form a positive and / or non-positive connection with the machining tool in the circumferential direction.

[0009] In this context, a "rotary impact mechanism" is understood to mean, in particular, an impact mechanism designed to convert the essentially continuous power output of a drive unit into an impact-like angular impulse. The rotary impact mechanism can be designed, in particular, as a cam-operated rotary impact mechanism or as a V-groove rotary impact mechanism. In this context, a "rotary impact impulse" is understood to mean, in particular, a periodically repeatable impact impulse. Preferably, the impact impulse is designed as a radial impulse and has a radially oriented component, the magnitude of which is at least 80 percent, preferably 90 percent, and preferably 95 percent of the total magnitude of the impact impulse. In this context, directional terms such as "axial," "radial," and "circumferential" are understood to refer specifically to an axis of rotation.The term "intended" is understood to mean, in particular, specially designed and / or equipped. The fact that an object is intended for a specific function is understood to mean, in particular, that the object fulfills and / or performs this specific function in at least one application and / or operating condition. A "planetary gear" is understood to mean, in particular, a gear that has at least one planet connected to a planet carrier, which is coupled radially outwards to a ring gear and / or radially inwards to a sun gear. The sun gear, the planet, and / or the ring gear may, in particular, be formed by round gears or by matched non-round gears. Several planetary gears may be connected in series, and / or several stages may be interposed between the planet gear and the ring gear.The term "ring gear" refers in particular to a gear wheel having a rim designed in the form of a cylindrical shell or a segmented cylindrical shell. As an alternative to using a planetary gear, the use of another gear design deemed suitable by a person skilled in the art, such as a spur gear, and / or the use of a combination of different gear designs is also conceivable.

[0010] Such a design allows for the provision of a generic attachment device with advantageous structural properties. In particular, the use of a planetary gear enables the provision of a suitably compact, cost-effective, efficient, and / or robust attachment for implementing rotary impact operation on a hand-held power tool. This advantageously expands the application range of a hand-held power tool. An attachment device can be provided that is compatible with various base devices, especially different hand-held power tools. An attachment device can be provided for a large number of different tools.

[0011] According to the invention, the rotary impact mechanism comprises at least one drive element having a connection area that can be connected to a tool holder of the hand-held power tool. A "tool holder" is understood to be a holder for at least one tool, for example, a bit. Preferably, the tool holder is designed as part of a machine interface intended to couple the attachment devices simultaneously to a housing unit and to an output shaft. In this context, a "drive element" is understood to be, in particular, an element designed to transmit and / or forward a drive movement, preferably a rotary movement and / or an angular momentum. Preferably, the drive element is designed to transmit a rotary movement in an axial direction and is, for example, designed as a shaft.Preferably, the drive element can be attached to the tool holder. This allows a rotary motion to be advantageously transferred from the hand-held power tool to the attachment device.

[0012] According to the invention, the drive element is at least partially formed integrally with a planetary gear carrier of the planetary gear set, and the drive element is at least partially designed as a spindle that can be connected axially movable and rotationally fixed to a tool holder of the hand-held power tool. "Integral" is understood to mean, in particular, at least a materially bonded connection, for example, by a welding process, an adhesive bonding process, an injection molding process, and / or another process that would appear appropriate to a person skilled in the art, and / or advantageously formed in one piece, such as by manufacturing from a single casting and / or by manufacturing using a single- or multi-component injection molding process, and advantageously from a single blank. Preferably, the drive element engages in a recess of the tool holder in a coupled state.It is also conceivable that the drive element has a receptacle into which, in a coupled state, an element of the tool holder engages. This allows the rotary impact mechanism to be connected to the hand-held power tool particularly easily, quickly, and reliably. A particularly simple rotary impact mechanism can be provided. A particularly compact rotary impact mechanism can be provided.

[0013] Furthermore, it is proposed that the planetary gear set have at least two selectable gear ratios. Preferably, the planetary gear set has a gear ratio of less than 1. In particular, the planetary gear set has a gear ratio between 0.1 and 0.8. This allows the rotational speed of the attachment device to be advantageously adapted to rotary impact operation. A particularly powerful attachment device can thus be provided.

[0014] Furthermore, it is proposed that the rotary impact mechanism include a switching unit for impact deactivation and / or impact activation. Preferably, the switching unit is designed for operator actuation. In particular, the switching unit comprises an actuating element arranged axially between the drill chuck and the coupling unit. An "impact deactivation" is understood to be a unit designed to deactivate, interrupt, and / or disengage an impact drive. Preferably, the attachment has a rotary drive that can be used independently of the impact deactivation. Alternatively, it is conceivable that the rotary impact mechanism does not have an impact deactivation device. In such a configuration, the attachment is permanently configured for rotary impact operation.Preferably, the switching unit is designed to disengage detent elements and / or detent areas of the rotary impact mechanism and / or to fix them in a mutually non-engaging position. This allows for a particularly flexible attachment device.

[0015] Furthermore, it is proposed that the attachment device include a coupling unit designed for a detachable, rotationally fixed connection to the housing of the hand-held power tool. This allows for a suitably secure connection between the attachment device and the hand-held power tool.

[0016] Furthermore, it is proposed that the attachment device include a fixing unit for securing a handle. Preferably, the fixing unit is compatible with a handle fixing unit of a hand-held power tool, thus advantageously allowing the use of a handle belonging to a hand-held power tool. This enables a conveniently simple mounting of a handle to the attachment device.

[0017] Furthermore, a handheld power tool system is proposed, comprising an attachment device according to the invention and at least one handheld power tool for driving the attachment device. Preferably, the handheld power tool is designed as a battery-powered handheld power tool. This allows for a handheld power tool system suitable for a wide range of applications. A large number of work scenarios and / or applications can be achieved. A particularly cost-effective handheld power tool system for impact operation can be provided. The use of a specially designed impact wrench can be avoided. A particularly lightweight and / or compact handheld power tool, especially a cordless screwdriver, can be provided for coupling with the attachment device. A particularly powerful handheld power tool system can be provided. drawing

[0018] Further advantages arise from the following drawing description. The drawings illustrate two exemplary embodiments. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0019] They show: Fig. 1 a side view of a system with an attachment device according to the invention and with a hand-held power tool, Fig. 2 a perspective view of a drive and working area of ​​the hand-held power tool, Fig. 3 a perspective detail view of a machine interface of the hand-held power tool, Fig. 4 a sectional view of the attachment device according to the invention along a drive and working axis and Fig. 5 a schematic representation of a non-inventive embodiment with a gear unit. Description of the exemplary implementations

[0020] Figure 1Figure 34a shows a hand-held power tool system comprising a hand-held power tool 12a and an attachment 10a, which includes a rotary impact mechanism 20a. The attachment 10a is designed for mounting on the hand-held power tool 12a and includes a coupling unit 14a for connecting the attachment 10a to the hand-held power tool 12a. The coupling unit 14a is designed for coupling to a tool holder 16a of the hand-held power tool 12a. The coupling unit 14a is designed for a detachable, rotationally fixed coupling to a tool housing unit 58a of the hand-held power tool 12a. The attachment 10a includes a tool holder 18a for receiving a tool. It is conceivable that the hand-held power tool system 34a includes further attachments designed for coupling to the hand-held power tool 12a.The attachment device 10a has a fixing unit 100a, which is designed to fix a handle 102a. The rotary impact mechanism 20a is designed, in at least one operating state, to generate a rotary impact impulse for a percussive drive of the tool holder 18a. The attachment device 10a comprises a housing unit 36a in which the rotary impact mechanism 20a is arranged. The rotary impact mechanism 20a has a switching unit 28a for switching off and / or switching on the impact.

[0021] The hand-held power tool 12a is designed as a cordless screwdriver in the present embodiment. The hand-held power tool 12a comprises an electric drive unit 38a, which includes an electric motor. The hand-held power tool 12a comprises an output shaft 32a, which is designed to transmit a torque and / or a rotary motion generated by the drive unit 38a (see Figure 1). Figure 2The hand-held power tool 12a is pistol-shaped in the present embodiment. The hand-held power tool 12a has a drive and working area 40a and a handle area 42a. The hand-held power tool 12a has a drive and working axis 44a and a handle axis 46a. The drive and working axis 44a and the handle axis 46a form an angle of approximately 80 degrees with each other. It is conceivable that the drive and working axis 44a and the handle axis 46a form an angle with a value in the range between 60 degrees and 90 degrees, or another value that would appear suitable to a person skilled in the art. It is also conceivable that the drive and working axis 44a and the handle axis 46a are aligned with each other.

[0022] The hand-held power tool 12a comprises a switching unit designed to switch the drive unit 38a on and / or off and / or to set the speed and / or torque of the hand-held power tool 12a. The switching unit has an actuating element 48a designed for user operation. The actuating element 48a is designed as a push-button switch. The hand-held power tool 12a comprises a torque limiter designed to set the maximum torque transmitted from the drive unit 38a to the output shaft 32a. The torque limiter includes an adjusting ring 50a designed for user operation. The hand-held power tool 12a comprises a gear unit 52a. The gear unit 52a is designed to translate the speed and / or torque of the drive unit 38a into the speed and / or speed of the tool holder 18a.The transmission unit 52a has a plurality of gears with different gear ratios. The hand-held power tool 12a includes a gear selector for setting a gear. The gear selector has an actuating element 54a for user operation. In this embodiment, the actuating element 54a is designed as a sliding element. The hand-held power tool 12a includes a direction-of-rotation selector for setting the direction of rotation of the output shaft 32a. The direction-of-rotation selector has an actuating element 56a for user operation. In this embodiment, the actuating element 56a is designed as a sliding element.

[0023] The hand-held power tool 12a comprises a tool housing unit 58a, which encloses and supports the drive unit 38a and the gear unit 52a. The tool housing unit 58a extends over the drive and working area 40a and the handle area 42a. The hand-held power tool 12a is designed to be powered by a battery device 60a. The hand-held power tool 12a has a battery interface unit for the battery device 60a. The battery interface unit for the battery device 60a is located at an end of the handle area 42a opposite the drive and working area 40a. The battery interface unit is designed to connect a housing unit 62a of the battery device 60a to the tool housing unit 58a of the hand-held power tool 12a in a tool-free, detachable manner.

[0024] The hand-held power tool 12a includes a machine interface 64a, which is provided for a preferably rotationally secured fastening of the attachment device 10a (see Figure 3The machine interface 64a has a fastening element 66a arranged on an end face of the tool housing unit 58a. The fastening element 66a is designed, at least partially, as a sleeve and / or ring. The fastening element 66a has at least one locking element 68a and at least two retaining elements 70a, 72a on its outer circumference. The locking element 68a preferably has at least one locking tooth, and the at least two retaining elements 70a, 72a are designed in the present embodiment in the manner of bayonets to form a bayonet connection. The machine interface 64a is designed for a mechanical connection of the attachment device 10a. The coupling unit 14a of the attachment device 10a is designed for a detachable mechanical coupling with the machine interface 64a.

[0025] The output shaft 32a exits the hand-held power tool 12a in the area of ​​the machine interface 64a. The output shaft 32a has a rotational axis that corresponds to the drive and working axis 44a of the hand-held power tool 12a. At one free end, the output shaft 32a forms the tool holder 16a of the hand-held power tool 12a. The tool holder 16a is designed to hold an interchangeable tool, for example, a tool bit, preferably with a screwdriver blade, or a hexagonal attachment. The tool holder 16a is designed as a multi-sided internal recess and has a polygonal cross-section. The tool holder 16a is designed as a hexagonal internal recess, for example, for holding a hex drill bit or a screwdriver bit.

[0026] The coupling unit 14a of the attachment device 10a is designed to interact with the machine interface 64a of the hand-held power tool 12a. The coupling unit 14a and the machine interface 64a are designed to connect the tool housing unit 58a of the hand-held power tool 12a and the housing unit 62a of the attachment device 10a securely and without tools. The machine interface 64a and the coupling unit 14a each have a positive locking area. The positive locking areas are designed to form a positive connection with each other. The machine interface 64a and the coupling unit 14a each have a frictional locking area. The frictional locking areas are designed to form a frictional connection with each other. The coupling unit 14a and the machine interface 64a are designed to latch together.In the present embodiment, the coupling unit 14a and the machine interface 64a form a bayonet connection. The coupling unit 14a has an actuating element 74a, which is designed to release the locking mechanism of the coupling unit 14a with the machine interface 64a of the hand-held power tool 12a. The tool holder 18a is designed to receive an insert tool.

[0027] The rotary impact mechanism 20a comprises a drive element 22a which has a connection area 24a which, in a state connected to the hand tool 12a by means of the coupling unit 14a, can be connected to the tool holder 16a of the hand tool 12a via a drive mechanism (see Figure 4The rotary impact mechanism 20a is designed as a V-groove rotary impact mechanism. The rotary impact mechanism 20a is designed to convert the continuous power output of the drive unit 38a of the hand-held power tool 12a into an impact-type rotational impulse. The energy output of the drive unit 38a, generated by a striker 104a of the rotary impact mechanism 20a against a corresponding anvil 106a, is transferred to the tooling tool by means of a high-intensity impulse. The anvil 106a is integrally formed with the tool holder 18a. The striker 104a is mounted to allow both axial and radial movement. The axial movement is controlled by V-shaped grooves 108a and drive balls 122a. A spring 110a ensures the return movement of the striker 104a.

[0028] The rotary impact mechanism 20a has a planetary gear 30a, which is designed to translate the rotational speed and / or torque of an output shaft 32a of the hand-held power tool 12a into the rotational speed and / or torque of the tool holder 18a. The planetary gear 30a is a single-stage design. The planetary gear 30a has a gear ratio of less than 1. The planetary gear 30a comprises a ring gear 88a, a planet carrier 82a, and a sun gear 90a. The drive element 22a is designed to transmit torque and / or rotary motion from the output shaft 32a of the hand-held power tool 12a to the planetary gear 30a. The drive element 22a is integrally formed with a planet carrier 82a of the planetary gear 30a. The rotary impact mechanism 20a has an intermediate shaft 112a, which is aligned at least substantially with the output shaft 32a of the hand-held machine tool 12a.The intermediate shaft 112a forms the sun gear 90a of the planetary gear 30a. Furthermore, the rotary impact mechanism 20a has a bearing 114a for supporting the drive element 22a and a bearing 116a for supporting the intermediate shaft 112a. The bearings 114a and 116a are designed as rolling bearings, specifically ball bearings.

[0029] The connecting area 24a is arranged at one end of the drive element 22a opposite the tool holder 18a. The connecting area 24a is designed to correspond to the tool holder 16a of the hand-held power tool 12a. The connecting area 24a has a cross-section that corresponds to the cross-section of the tool holder 16a of the hand-held power tool 12a. In the present embodiment, the connecting area 24a has an outer circumference in the form of a regular hexagon. When connected to the hand-held power tool 12a, the connecting area 24a partially engages the tool holder 16a. In the present embodiment, the connecting area 24a and the tool holder 16a form a plug connection.Alternatively, it is conceivable that the connection area 24a has a drive receptacle, and the output shaft 32a engages in the drive receptacle of the connection area 24a in a connected state. The housing unit 36a of the attachment device 10a has a housing element 118a which is designed to support the rotary impact mechanism 20a against the tool holder 16a of the hand-held power tool 12a in at least one operating state. In the present embodiment, the housing element 118a forms engagement means 120a of the coupling unit 14a.

[0030] In the Figure 5Another embodiment is shown. The following descriptions and drawings are essentially limited to the differences between the embodiments, whereby with regard to identically designated components, in particular components with the same reference numerals, reference is also generally made to the drawings and / or the description of the other embodiments, in particular the Figures 1 to 4 , can be referenced. To distinguish the embodiments, the letter a is the reference numeral of the embodiment in the Figures 1 to 4 recreated. In the exemplary embodiment of the Figure 5 The letter a is replaced by the letter b.

[0031] Figure 5Figure 1 shows a schematic representation of a further embodiment of an attachment device 10b, which includes a rotary impact mechanism 20b. The attachment device 10b is designed for mounting on a hand-held power tool 12b (not shown in detail) and includes a coupling unit 14b for coupling to the power tool 12b. The coupling unit 14b is designed for coupling to a tool holder 16b of the power tool 12b. The attachment device 10b includes a tool holder 18b for receiving a tool. The rotary impact mechanism 20b is designed, in at least one operating state, to generate a rotary impact impulse to drive the tool holder 18b. The attachment device 10b includes a housing unit 36b in which the rotary impact mechanism 20b is arranged. The tool holder 18b is designed to receive a tool.

[0032] The attachment device 10b comprises a two-stage planetary gear unit 30b with a first gear stage 76b and a second gear stage 78b. The first gear stage 76b comprises an input sun gear 80b, a planet carrier 82b, a plurality of planet elements 84b, 86b, and a ring gear 88b fixed to the housing. The second gear stage 78b comprises a sun gear 90b non-rotatably connected to the planet carrier 82b of the first gear stage 76b, a planet carrier 92b, a plurality of planet elements 94b, 96b, and a switching ring gear 98b. The planetary gear unit 30b has two selectable gear ratios. In one of the gear ratios, the switching ring gear 98b is fixed to the housing. In the present embodiment, the switching ring gear 98b has engagement means not shown in detail, which are provided in the first gear to form a positive connection with the housing unit 36b of the attachment device 10b.In another gear stage, the ring gear 98b is rotationally fixed to the planet carrier 82b of the first gear stage 76b. Simultaneously, the planetary elements 94b and 96b of the next gear stage 78b are engaged with the ring gear 98b. The second gear stage 78b is short-circuited in this next gear stage. The planet carrier 92b of the next gear stage 78b rotates at the same speed as the sun gear 90b in this next gear stage.

Claims

1. Attachment device for arrangement on a hand-held power tool (12a), having a tool receptacle (18a) for receiving an insert tool, and having at least one rotary impact mechanism (20a) which, in at least one operating state, is intended to generate a rotary impact impulse for impact driving of the tool receptacle (18a), wherein the rotary impact mechanism (20a) has at least one planetary transmission (30a) which is intended to translate a rotational speed and / or a torque of an output shaft (32a) of the hand-held power tool (12a) into a rotational speed and / or a torque of the tool receptacle (18a), characterized in that the rotary impact mechanism (20a) comprises at least one drive element (22a) which is formed at least partially as a spindle and which has a connecting region (24a) which is connectable in terms of drive to an insert-tool receptacle (16a) of the hand-held power tool (12a), wherein the spindle is configured to be axially movably and rotationally conjointly connectable to the insert-tool receptacle (16a) of the hand-held power tool (12a) and the drive element (22a), formed at least partially as the spindle, is formed at least partially in one piece with a planet-gear carrier (82a) of the planetary transmission (30a).

2. Attachment device according to one of the preceding claims, characterized in that the planetary transmission has at least two switchable transmission gears.

3. Attachment device according to either of the preceding claims, characterized in that the planetary transmission (30a) has a transmission ratio of less than 1.

4. Attachment device according to one of the preceding claims, characterized in that the rotary impact mechanism (20a) has a switching unit (28a) for impact deactivation and / or impact activation.

5. Attachment device according to one of the preceding claims, characterized by a fixing unit which is intended for fixing a handle.

6. Attachment device according to one of the preceding claims, characterized in that the drive element (22a) is pluggable onto the insert-tool receptacle (16a).

7. Attachment device according to one of the preceding claims, characterized in that the drive element (22a), in a coupled state, engages into a clearance of the insert-tool receptacle (16a).

8. Attachment device according to one of the preceding claims, characterized by a coupling unit (14a) which is intended for releasable, rotationally fixed coupling to a tool housing unit (58a) of the hand-held power tool (12a) and for coupling at the insert-tool receptacle (16a) of the hand-held power tool (12a).

9. Attachment device according to Claim 8, characterized in that the coupling unit (14a) has an actuating element (74a) which is intended to release a latching connection of the coupling unit (14a) to a machine interface (64a) of the hand-held power tool (12a).

10. Attachment device according to one of the preceding claims, characterized in that the connecting region (24a) has a cross section which is configured in a manner corresponding to a cross section of the insert-tool receptacle (16a) of the hand-held power tool (12a).

11. Attachment device according to one of the preceding claims, characterized in that a housing unit (36a) of the attachment device (10a) has a housing element (118a) which is intended to support the rotary impact mechanism (20a) against the insert-tool receptacle (16a) of the hand-held power tool (20a) in at least one operating state.

12. Hand-held power tool system having an attachment device (10a) according to one of the preceding claims, and having at least one hand-held power tool (12a) for driving the attachment device (10a).

13. Hand-held power tool system according to Claim 12, characterized in that the hand-held power tool (12a) is designed as a rechargeable-battery-operated hand-held power tool.

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