Machine tool with decoupling device

Abstract

The invention relates to a machine tool (1), in particular a hammer drill or chisel hammer, comprising a housing (5) having a gripping region (7, 27), and an assembly (9) comprising an impact mechanism (11) and a drive device (13), the assembly (9) being arranged substantially within the housing (5) and being arranged displaceably relative to the housing (5). The centre of gravity (15) of the assembly (9) is arranged at a distance from an impact axis (19) defining the longitudinal direction (Z). At least one front decoupling device (23) and at least one rear decoupling device (25) are arranged relative to the longitudinal axis (Z). The decoupling means (23, 25) are operatively connected, on the one hand, to the housing (5) and, on the other hand, to the assembly (9). The at least one rear decoupling device (25) is designed such that the assembly (9) can be moved relative to the housing (5) in all three spatial directions (X, Y, Z) and has a spring characteristic and / or a damping characteristic in all three spatial directions (X, Y, Z).

Description

Technical Field

[0001] The invention relates to a machine tool, in particular a drill hammer and / or a chisel hammer, of the type described in more detail in the preamble to claim 1 . Background Art

[0002] DE 10 2020 216 538 A1 discloses a hammer drill and / or a chisel hammer having an outer housing and an inner housing. The inner housing is arranged in the outer housing, wherein the inner housing has a drive unit and an impact unit. A vibration damping unit having a vibration damping element for damping vibrations occurring during operation is provided, by means of which a main handle connected to the outer housing is decoupled from the inner housing. The inner housing is rotatably mounted relative to the outer housing about an axis of rotation arranged in the region of the instantaneous center of rotation of the impact unit.

[0003] In this embodiment, the mobility of the inner housing relative to the outer housing is limited to an axis of rotation arranged in the region of the instantaneous center of rotation of the impact unit. However, the instantaneous center of rotation may not be precisely determined or may fluctuate during operation of the machine tool. In this case, the damping of the outer housing relative to the inner housing is reduced. Summary of the invention

[0004] It is an object of the present invention to provide a machine tool, in particular a drill hammer or a chisel hammer, in which improved damping properties of the outer housing can be achieved in all operating states with respect to the assembly comprising the impact mechanism.

[0005] This object is achieved by the subject matter of independent claim 1. Further advantageous embodiments of the invention can be found in the corresponding dependent claims.

[0006] A machine tool, in particular a hammer drill or a chisel hammer, is provided, which has a housing with a handle area and an assembly comprising an impact mechanism and a drive device, wherein the assembly is arranged essentially within the housing and is arranged movably relative to the housing, wherein the center of gravity of the assembly is arranged at a distance from an impact axis defining a longitudinal direction, wherein at least one front decoupling device and at least one rear decoupling device are provided relative to the longitudinal axis, wherein the decoupling devices are operatively connected to the housing and to the assembly.

[0007] According to the invention, it is proposed that the at least one rear decoupling device is designed such that the component is movable relative to the housing in all three spatial directions and has spring and / or damping properties in all three spatial directions.

[0008] The machine tool designed according to the invention has the following advantages: In all operating states of the machine tool, the housing is protected to the desired extent from vibrations, oscillations, etc. occurring in the region of the components during operation of the machine tool, and vibrations occurring in this region are damped to the desired extent. This is achieved in that the rear decoupling device or the vibration protection device has spring and / or damping properties in all spatial directions of the Cartesian coordinate system. In this regard, vibrations are effectively reduced in chiseling operation, in which a chisel connected to the tool holder is moved back and forth in an oscillating manner in the direction of the impact axis, and in hammer drilling operation, in which the tool additionally performs a rotational movement about the impact axis.

[0009] During drilling or chiseling operations, vibrations or accelerations are generated by the interaction between the ground surface and the tool connected to the tool holder. The maximum acceleration acts here in the direction of the impact axis or in the longitudinal direction or in the Z direction. Due to the angular construction of the machine tool, in which the center of mass of the assembly does not lie on the impact axis, vibrations also occur during operation of the machine tool in the vertical direction, transversely to the impact axis or in the Y direction. Furthermore, vibrations such as those caused by unbalanced forces of the drive unit also occur in the transverse direction or in the X direction during operation of the machine tool.

[0010] With the solution according to the invention, during operation of the machine tool, it is easily possible for a user, for example holding the machine tool in at least one gripping area, in particular in this gripping area, to adjust to very low values, which allows prolonged work with the machine tool according to the invention.

[0011] The three spatial directions are defined in particular by the longitudinal direction, the transverse direction and the vertical direction of the machine tool. The longitudinal direction or Z direction, the transverse direction or X direction and the vertical direction or Y direction are perpendicular to each other, the longitudinal direction corresponding to the impact axis. The plane spanned by the transverse direction and the vertical direction is perpendicular to the longitudinal direction.

[0012] In an advantageous embodiment of the machine tool according to the invention, it is provided that the rear decoupling device has a first decoupling device which has a spring and / or damping property in the transverse and vertical direction of the machine tool, and a second decoupling device is provided which has a spring and / or damping property in the longitudinal direction. It has been shown that with such an embodiment, particularly good damping properties can be achieved in all operating states and thus it can be advantageously achieved that small vibrations act on the user during operation. It is particularly advantageous if the first decoupling device additionally has a spring and / or damping property in the longitudinal direction.

[0013] In order to achieve an advantageous spring characteristic and / or damping characteristic in a plane defined by the transverse direction and the vertical direction, it is advantageous if the first decoupling device has a decoupling element extending in the circumferential direction relative to an axis of the decoupling device extending in the longitudinal direction. By means of such a decoupling element, the spring and / or damping characteristic in the transverse direction and the vertical direction can be set in a simple manner.

[0014] In an advantageous embodiment of the machine tool according to the invention, the decoupling element has a cross section which is constant in the circumferential direction of the axis or which varies in the circumferential direction of the axis. In this way, substantially identical spring and / or damping characteristics can be set in the vertical direction and in the transverse direction. Alternatively, different spring and / or damping characteristics in the vertical direction and in the transverse direction can be set in a simple manner by means of a cross section of the decoupling element which varies in the circumferential direction, depending on the application. For this purpose, the decoupling element has, for example, a varying material thickness in the circumferential direction.

[0015] The decoupling element can be designed, for example, with an elastomer, in particular with a dynamic foam. In principle, any material with the desired spring and / or damping properties can be used.

[0016] In an advantageous embodiment of the machine tool according to the invention, the first decoupling device has an element operatively connected to the housing, which element can be displaced substantially in the longitudinal direction relative to the element operatively connected to the assembly. Thus, a desired large displacement of the assembly relative to the housing in the longitudinal direction is achieved in a simple manner. For example, it can be provided that the element fixed to the housing is designed as a steel pin, which is connected to the housing in a form-fitting manner, in particular threaded, wherein the element operatively connected to the assembly can be designed, for example, as a sliding bushing, representing a sliding fit for this purpose. It can also be provided that an element operatively connected to the structural unit is provided, which element can be displaced substantially in the longitudinal direction relative to the element operatively connected to the housing.

[0017] For example, in order to reliably prevent undesired impacts on the housing in the area of ​​the first decoupling device during operation of the component in all operating states, an element operatively connected to the housing or an element operatively connected to the component can be connected to the housing or the component under pretension by means of a decoupling element.

[0018] Particularly good damping properties can be achieved if the first decoupling device is arranged between the housing and the assembly in the region facing away from the tool holder of the machine tool, in particular at a particularly large distance from the front decoupling device arranged in the region of the tool holder. In principle, however, the first decoupling device can be arranged at any position between the housing and the assembly.

[0019] In an advantageous embodiment of the machine tool according to the invention, the rear decoupling device has at least two first decoupling devices, which in particular have a substantially identical design, which are each arranged at different positions between the housing and the assembly. This makes it possible to achieve particularly advantageous spring and / or damping characteristics. The position and number of the first decoupling devices can in principle be selected as desired, depending on the application.

[0020] In an advantageous embodiment of the machine tool according to the invention, the rear decoupling device comprises at least a first decoupling device, a second decoupling device and a third decoupling device, each of which is arranged between the assembly and the housing, wherein the first decoupling device has a spring characteristic and / or a damping characteristic in the upward direction of the machine tool, wherein the second decoupling device has a spring characteristic and / or a damping characteristic in the lateral direction of the machine tool, and wherein the third decoupling device has a spring characteristic and / or a damping characteristic in the longitudinal direction. It has been shown that particularly advantageous spring and / or damping characteristics can be achieved in this way. All decoupling devices may additionally have spring and / or damping characteristics in other directions. In addition, in addition to the direction in which their spring and / or damping characteristics act, all decoupling devices may allow the assembly and the housing to move relative to each other in other directions.

[0021] In an advantageous structural embodiment, the first decoupling device has two sliding elements, which are mounted in a guide fixed to the housing and are connected essentially in the vertical direction by means of at least one spring device, in particular by means of at least two spring devices. Preferably, the sliding elements are mounted so that the component can be displaced in the longitudinal direction relative to the housing by means of the sliding elements. If at least two spring devices are provided, a rotational movement of the component relative to the housing, in particular a rotational movement about a transverse direction, can also be achieved via the spring devices. In order to be able to set a desired pretensioning of the sliding elements relative to one another, at least one, in particular two, limiting elements can be provided, which limit the movement of the sliding elements relative to one another in the vertical direction.

[0022] In an advantageous embodiment of the machine tool according to the invention, it can be provided that the second decoupling device has a decoupling element which is designed to rotate relative to an axis extending in the transverse direction and is arranged on an element mounted opposite the component, which element is guided on an element fixed to the housing. A second decoupling device designed in this way can make it possible to achieve the desired spring and / or damping characteristics in the transverse direction and the possibility for displacing the component relative to the housing in a plane defined by the vertical direction and the longitudinal direction.

[0023] In an advantageous embodiment of the machine tool according to the invention, the front decoupling device enables movement of the component relative to the housing in all three spatial directions. Here, the front decoupling device can be designed as a sliding bearing with a clearance fit.

[0024] In an advantageous embodiment of the invention, by means of which rattling of the assembly relative to the housing is reliably prevented during operation, the front decoupling device can have a first sliding element fixed to the housing and a second sliding element interacting with the assembly, wherein the sliding element operatively connected to the assembly is prestressed in a radial direction relative to the longitudinal direction. For example, the prestressing can be achieved by means of an annular element extending circumferentially relative to the longitudinal direction or by means of a curvature in the sliding element operatively connected to the assembly in a radial direction relative to the longitudinal direction.

[0025] In an advantageous embodiment of the invention, the sliding element of the front decoupling device fixed to the housing can be designed to have a large rigidity, so that the sliding element fixed to the housing does not deform, or does not deform to an undesirably large extent, for example when the handle device is externally connected by means of a clamping band. For this purpose, the sliding element fixed to the housing can be designed, for example, from a metal material, in particular as a steel bushing.

[0026] In order to minimize friction during displacement of the assembly relative to the housing in the longitudinal direction, the sliding element operatively connected to the assembly may be realized with plastic and the sliding element fixed to the housing with a metallic material.

[0027] Here, the sliding element operatively connected to the component can be a so-called Slydring® or a ring which is grooved in the circumferential direction, in particular a steel ring or a plastic ring, in particular with a sliding paint coating.

[0028] In an advantageous embodiment of the machine tool according to the invention, the front decoupling device comprises a first sliding element fixed to the housing, a second sliding element fixed to the assembly, and a third sliding element, wherein the third sliding element is displaceable substantially in the longitudinal direction relative to the second sliding element fixed to the assembly, and wherein the first sliding element has a longitudinally curved sliding surface corresponding to the sliding surface of the third sliding element, the assembly being rotatable substantially in a transverse direction and / or in a vertical direction relative to the housing by the cooperation of the sliding surface of the first sliding element with the sliding surface of the third sliding element. This design of the front decoupling device allows in particular a large displacement of the structural unit in the longitudinal direction relative to the housing and a rotation of the assembly in the region of the front decoupling device in a transverse direction and / or in a vertical direction relative to the housing.

[0029] The third sliding element can be composed of a plurality of parts in the circumferential direction, in particular two, three, four or more parts, in order to facilitate the assembly of the third sliding element, in particular on the first sliding element. In order to connect the plurality of parts, the individual parts can have grooves on the inner side with end regions widening in the circumferential direction, via which adjacent parts of the third sliding element can be connected to each other via the connecting element.

[0030] In an advantageous embodiment of the machine tool according to the invention, at least one supporting device arranged in the transverse direction between the component and the housing is provided, the supporting device having a supporting element prestressed in the transverse direction. The supporting device is a decoupling device, by means of which swings and / or vibrations occurring in the region of the component, in particular during operation of the machine tool, are suppressed and transmitted to the housing to a lesser extent. This makes it possible to achieve rattling of the component by means of arranging such a supporting device between the component and the housing in this region, in particular on both sides in the transverse direction, wherein, in addition, a displacement of the component relative to the housing in the vertical direction is easier. An embodiment with low friction provides that the supporting device has a metallic supporting element, which is fixedly arranged on the housing and interacts with a plastic element of the component. A functional reversal is also possible.

[0031] To limit displacement of the assembly relative to the housing, stops may be provided on both sides in all directions, fixed to the housing and / or to the assembly, wherein the number and position of the stops may vary as required in each direction, depending on the application.

[0032] Other advantages can be seen in the following description of the drawings. Different exemplary embodiments of the present invention are shown in the drawings. The drawings, the description and the claims contain many combined features. It will also be convenient for those skilled in the art to consider these features individually and to combine these features to form meaningful additional combinations. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In the attached picture: Figure 1 A simplified sectional side view of a first embodiment of a machine tool designed as a hammer drill, the machine tool having an outer housing and an assembly arranged in the housing, the assembly comprising an impact device and a drive device, the assembly being displaceable relative to the housing by means of a front decoupling device and a rear decoupling device, the assembly being shown in a position in which no external forces act; Figure 2 Shows the corresponding machine tool Figure 1 , the assembly is shown in a rear position against the stop when an external force is applied; Figure 3 Show according to Figure 1 and Figure 2 A cross-sectional view of a machine tool in a vertical direction; Figure 4 Shown corresponding to Figure 1 A cross-sectional view of a machine tool, wherein when an external force is applied, the assembly rotates relative to the housing about a transverse axis; Figure 5 Shown corresponding to Figure 3 A cross-sectional view of a machine tool, wherein when an external force is applied, the assembly rotates relative to the housing about a vertical axis; Figure 6 Show according to Figure 1 A cross-sectional view of a machine tool; Figure 7 Shows no basis for components Figure 6 A cross-sectional view of a machine tool; Figure 8 A cross-sectional view showing the assembly-side elements of the rear decoupling device; Fig. 9 Another cross-sectional view showing the assembly-side element of the rear decoupling device; Fig.10 Show according to Figure 6 A cross-sectional view of a machine tool of FIG. 1 in which the support device can be seen in more detail; Fig.11 Show according to Figure 6 A 3D view of the machine tool, where the support device can be seen in more detail; Fig.12 Show according to Figure 6 A cross-sectional view of a first embodiment of a front decoupling device for a machine tool; Fig.13 Show according to Fig.12 3D view of the front decoupling device; Fig.14 Show according to Figure 6 A three-dimensional view of an assembly of a machine tool having an alternatively designed front decoupling device; Fig.15 Show according to Fig.14 A sectional view of a front decoupling device; Fig.16 Show separately according to Fig.14 A three-dimensional view of the components of the front decoupling device; Fig.17 Show according to Fig.14 A three-dimensional view of the elements of the front decoupling device in an alternative embodiment; Fig.18 A three-dimensional view of a machine tool showing an alternative design; Fig.19 Show according to Fig.18A three-dimensional view of a detail of a machine tool, wherein the rear decoupling device can be seen in more detail; Fig. 20 Show according to Fig.18 A cross-sectional view of a portion of a rear decoupling device; Fig.21 Show according to Fig.18 A sectional view of a front decoupling device of a machine tool; Fig. 22 Show according to Fig.21 A three-dimensional view of a first sliding element of a front decoupling device; Fig.23 Show according to Fig.21 A three-dimensional view of the third sliding element of the front decoupling device; Fig.24 A three-dimensional view showing an alternative design of the rear decoupling device; Fig.25 Show according to Fig.24 a rear view of the rear decoupling device; and Fig.26 Show according to Fig.24 and Fig.25 Plan view of the rear decoupling device.

[0034] Exemplary embodiments Figures 1 to 5 A first embodiment of a machine tool 1 is shown, which in the present case is realized as a hammer drill or a combination hammer, but in alternative embodiments can also be realized as a chiseling hammer or the like, for example.

[0035] In the present case, the machine tool 1 is designed as a cordless machine tool with a storage battery 3 , but in an alternative embodiment can be provided for mains operation.

[0036] Here, the machine tool 1 has an angled design and has a housing 5 with a D-shaped rear gripping area 7. The housing 5, which can be realized in one or more parts, is fixedly connected to the gripping area 7 that can be gripped by the user. In the present case, the housing 5 is divided in the longitudinal direction Z and has a so-called pot configuration. Alternatively, the housing 5 can also have, in particular, two housing halves, which can be connected to each other in the transverse direction X and have a so-called shell configuration.

[0037] Arranged in the housing 5 is a structural unit or assembly 9 which has a conventionally designed striking mechanism 11 and a drive device 13 designed as an electric motor, which is designed to drive the striking mechanism 11. In the present case, the assembly 9 is designed in an L-shape.

[0038] With the aid of the assembly 9, drilling or chiseling operations are possible, whereby in the chiseling operation the tool 17 is moved back and forth in an oscillating manner in the direction of the impact axis. In the drilling or hammer drilling operation, the tool also performs a rotational movement about the impact axis.

[0039] The machine tool 1 has, in a known manner, a tool holder 16 , via which a tool 17 , such as a chisel or the like, can be operatively connected to the structural unit 9 in a removable manner.

[0040] The figures also show a longitudinal direction, designated as Z or Z-direction, a vertical direction, designated as Y or Y-direction, and a transverse direction, designated as X or X-direction. X, Y and Z are axes of a Cartesian coordinate system and are perpendicular to each other. In the absence of external forces, the longitudinal direction Z coincides with the impact axis, which is defined by the central axis of the tool or tool holder 16.

[0041] In the embodiment shown, the center of gravity of the structural unit 9 is designated by 15 , which center of gravity is arranged below the longitudinal direction Z relative to the vertical direction Y in the shown view and is therefore spaced apart from the longitudinal direction Z.

[0042] The assembly unit 9 can have a separate inner housing 21 which in particular comprises the striking mechanism 11 and the drive device 13 , or the striking mechanism 11 and the drive device 13 can in particular be arranged almost completely within the inner housing.

[0043] For example, Figure 1 A front decoupling device 23 and a rear decoupling device 25 are shown, which can in principle be designed with one decoupling device or multiple decoupling devices. In the embodiment shown, the front decoupling device 23 is arranged in front of the rear decoupling device 25 in the longitudinal direction Z, i.e. closer to the tool holder 16 and in the area facing away from the rear gripping area 7.

[0044] For example, in Figure 1 and Figure 3 In the figure, a front gripping area 27 or a side handle can be seen, which in the present case can be releasably brought into operational connection with the housing 5 in the region of the front decoupling device 23, for example by means of a clamping band. In the present case, the front gripping area 27 extends approximately in the transverse direction X, but can in particular be arranged on the housing 5 so as to be continuously adjustable in the circumferential direction relative to the longitudinal direction Z.

[0045] The structural unit 9 is mounted relative to the housing 5 via the front decoupling device 23 and also via the rear decoupling device 25, wherein the structural unit 9 is displaceable relative to the housing 5 in the region of the front decoupling device 23 and in the region of the rear decoupling device 25 in the longitudinal direction Z, in the transverse direction X and in the vertical direction Y. The possibility of displacement in the longitudinal direction Z is, for example, a maximum of approximately 10 mm, but in other embodiments it can also be up to 20 mm or more. In the present case, the possibility of displacement in the transverse direction X and in the vertical direction Y is essentially the same, wherein in the present case the possibility of displacement in the longitudinal direction Z is approximately 7 times greater than the possibility of displacement in the transverse direction X and in the vertical direction Y.

[0046] In order to define the maximum movement path in the transverse direction X, in the vertical direction Y and in the longitudinal direction Z, stops 37 are provided in the present case, each of which defines a defined end position of the structural unit 9 relative to the housing 5. The number and position of the stops 37 can in principle be freely selected, wherein preferably at least one, in particular two, stops 37 are provided on both sides of the structural unit 9 for each direction X, Y and Z.

[0047] During the drilling or chiseling operation of the machine tool, vibrations or accelerations are generated due to the interaction between the ground to be processed and the tool 17, which act primarily in the direction of the impact axis. Due to the angular design of the machine tool 1, in which the center of mass 15 of the structural unit 9 does not lie on the impact axis or longitudinal axis Z, vibrations or accelerations are also generated transversely to the impact axis in the vertical direction Y. Vibrations or accelerations in the transverse direction X also occur during operation of the machine tool 1, for example, due to unbalanced forces in the region of the drive device 13.

[0048] During operation of the machine tool 1, vibrations and accelerations occur in the region of the structural unit 9. These can be transmitted to the housing 5 with the front gripping area 27 and the rear gripping area 7 via the front decoupling device 23 and the rear decoupling device 25. The aim is to reduce or suppress the vibrations or accelerations occurring in the region of the structural unit 9 during operation of the machine tool 1 as much as possible by means of the decoupling devices 23, 25.

[0049] Component 9 in Figure 1 1 is shown in a rest position in which the machine tool 1 is not in operation or the assembly 9 contacts the front stop 37a in the front position. Figure 2 , the assembly 9 is shown in the rear end position and with maximum deflection in the longitudinal direction Z, wherein the assembly 9 is at the stops 37 b and 37 c.

[0050] In accordance with Figures 1 to 5 In the exemplary embodiment of , a first lateral stop 37 d and a second lateral stop 37 e are provided, which limit the movement path of the component 9 relative to the housing 5 in the transverse direction X.

[0051] Furthermore, in the present case an upper stop 37 f and a lower stop 37 g are provided which limit the movement path of the component 9 in the vertical direction Y relative to the housing 5 .

[0052] In the following, first the rear decoupling device 25 is described in more detail.

[0053] The rear decoupling device 25 has two first decoupling devices 31 , 33 and a second decoupling device 35 .

[0054] The second uncoupling device 35 of the rear uncoupling device 25 has a spring and / or damping characteristic in the longitudinal direction Z and is realized here as a spring device with an effective axis substantially in the longitudinal direction Z.

[0055] The spring device 35, which is designed here as a cylindrical helical spring, is arranged relative to Figure 1 The housing 5 in the housing presses the assembly 9 into a front position in which the assembly 9 abuts the front stop 37a. Figure 2 The spring means 35 are shown in a maximum tensioned position. The spring means 35 assumes this position when the assembly 9 is in a rear end position relative to the housing 5, in which position the assembly abuts the rear stops 37b, 37c.

[0056] A plurality of spring devices 35 may also be provided, wherein for example two spring devices 35 may be provided which are arranged at a distance from one another in the transverse direction X. Alternatively or additionally, two spring means 25 which are arranged at a distance from one another in the vertical direction Y may also be provided.

[0057] In accordance with Figures 1 to 5 In the embodiment of the present invention, two first decoupling devices 31, 33 of substantially identical structure are provided, the first decoupling device 31 being arranged between the assembly 9 and the housing 5 on the left side of the machine tool 1, and the first decoupling device 33 being arranged between the assembly 9 and the housing 5 on the right side of the machine tool 1. In principle, only one such first decoupling device 31, 33 can also be provided, which is arranged at any position between the assembly 9 and the housing 5. It is particularly advantageous that the distance in the longitudinal direction Z between the decoupling device 29 of the front decoupling device 23 and the first decoupling device 31 and / or 33 of the rear decoupling device 25 is as large as possible.

[0058] exist Figure 4 and Figure 5, it is shown in a highly exaggerated manner that during operation of the machine tool 1 the assembly 9 can rotate relative to the housing 5 about an axis extending in the transverse direction X and about an axis extending in the vertical direction Y. A rotation about an axis extending in the longitudinal direction Z is also possible. The front decoupling device 23 and the rear decoupling device 25 are designed such that they enable such a rotation and in particular can also thereby damp transmitted vibrations or accelerations.

[0059] exist Figures 1 to 5 , further first decoupling device 36 is also shown, which is arranged between assembly 9 and housing 5 in the lower region of machine tool 1 in vertical direction Y. This further first decoupling device 36 is optional and can improve the spring and / or damping properties.

[0060] exist Figures 6 to 9 In FIG. 2 , the rear decoupling device 25 has a single first decoupling device 31 in addition to two second decoupling devices 35 designed as spring devices.

[0061] according to Figures 6 to 9 The first decoupling device 31 corresponds in structure to Figures 1 to 5 The first decoupling device 31 and 33 are described in more detail below. Figures 6 to 9 The first decoupling device 31 is provided.

[0062] The first decoupling device 31 has a first sliding element 39, which is designed here as a pin-shaped element with a center axis 49. The pin-shaped element 39, which is designed, for example, as a steel pin, is here connected to the housing 5 by means of a threaded connection via a thread 41 arranged in the rear end region in the longitudinal direction Z. The first decoupling device 31 also includes a second sliding element 43, which cooperates with the first sliding element 39 and serves as a sliding partner for the first sliding element 39 and is designed in the present case as a sliding bushing. The sliding bushing 43 interacts with a bearing block 47, which is fixed to the assembly via the decoupling element 45. In the present case, the bearing block 47 is connected to the transmission housing of the assembly 9 by a positive fit.

[0063] Here, the decoupling element 45 is fixed relative to the sliding bushing 43 in the direction of the central axis 49. Preferably, the sliding bushing 43, which is made of plastic in particular, is clamped into the decoupling element 45 for this purpose. In the region radially outside the central axis 49, the decoupling element is fixed in the direction of the central axis 49 via the bushing 51 and the bearing block 47.

[0064] It can also be provided that the decoupling element 45 is adhesively bonded to the sliding bushing 43 and / or to the bearing block 47 .

[0065] The decoupling element 45 is in this case tubular, with a substantially constant wall thickness. In an alternative embodiment, the decoupling element 45 can have a varying wall thickness circumferentially to the central axis 49 .

[0066] In the present case, the decoupling element 45 is made of an elastomer. Figure 8 In the rest position shown, the decoupling element 45 has a pretension in the radial direction of the center axis 49 in order to achieve the desired radial stiffness in the transverse direction X and in the vertical direction Y.

[0067] In the region of the first decoupling device 31 , a rotation of the component 9 relative to the housing 5 is possible.

[0068] In the present case, a spring receiving spindle for the upper spring device 33 , which is realized as a compression spring in the vertical direction Y, is attached to the bearing block 47 .

[0069] In the present case, two front stops 37 a are provided which are realized as rubber buffers and are connected to the transmission housing.

[0070] Apart from Figure 6 In addition to the embodiment with the first decoupling device 31 shown in the figure, another first decoupling device with substantially the same structure can also be provided, which can be arranged in a region of the component 9 that is lower with respect to the vertical direction Y and in a region behind with respect to the longitudinal direction Z. Specifically, such another first decoupling device can be arranged in the region of the drive device 13.

[0071] Figure 24 to Figure 26 An alternative embodiment of the rear decoupling device 25 is shown. The first decoupling device 53 is designed here with an asymmetrical metal leaf spring or leaf spring 55, which is preferably coated with a sliding paint. A steel pin 57 connected to the housing 9 serves as a sliding partner for the leaf spring 55, wherein the leaf spring 55 has a steel pin 57 in the end region at least in the region. The leaf spring 55 is arranged on the component 9 by means of a bearing block 59, wherein the bearing block 59 in the present case has two spring pins 61a, 61b for interacting with the two spring devices 33.

[0072] Fig.10 and Fig.11 A first lateral support device 63 and a second lateral support device 65 are shown. The first lateral support device 63 and the second lateral support device 65 are substantially symmetrical and structurally identical to each other, wherein the first lateral support device 63 is described as representative of the second lateral support device 65 in the following.

[0073] The support means 63 , 65 may represent part of the rear decoupling means 25 and thus also a decoupling means for inhibiting a movement of the housing 5 relative to the assembly 9 during operation of the machine tool 1 .

[0074] The first lateral support device 63 is arranged between the component 9 and the housing 5 in the transverse direction X. The first lateral support device 63 has a support element 67 which is prestressed in the transverse direction X and which is connected on the one hand to the fixed housing by means of a positive connection and on the other hand in the present case by means of two fastening areas or webs arranged at a distance from each other in the vertical direction Y to a first sliding element designed as a sliding plate 69.

[0075] The stiffness of the support element 67 in the transverse direction X can in this case be easily adjusted by a corresponding choice of material for the support element 67 , which is realized, for example, with an elastomer, and / or by a corresponding shaping of the support element 67 .

[0076] The sliding plate 69 is, for example, glued to the support element 67 and extends substantially in the vertical direction Y and is provided for interaction with a second sliding element 71 which in the present case is formed by a housing 73 of the drive device 13 which is realized from plastic.

[0077] The interaction of the sliding plate 69 and the housing 73 of the drive device 13 enables a wear-free or low-wear displacement of the component 9 relative to the housing 5 .

[0078] Due to the first and second lateral support means 63, 65, in the event of high torques occurring between the assembly 9 and the housing 5 during operation, the large forces present can be absorbed and hard stops which could cause rattling can be reliably avoided. The elastic bearing is slightly prestressed in the transverse direction X, so that no play is required between the assembly 9 and the housing 5 in the transverse direction X.

[0079] exist Fig.12 and Fig.13 A first embodiment of the decoupling device 29 of the front decoupling device 23 is shown in more detail in FIG.

[0080] The front decoupling device 29 has a first sliding element 75 fixed to the housing and a second sliding element 77 interacting with the assembly 9. The second sliding element 77 is arranged in a groove 79 of the assembly and is fixed relative to the assembly essentially in the longitudinal direction Z. The second sliding element 77 is prestressed in the radial direction relative to the longitudinal direction Z. For this purpose, a further groove 81 is provided in the radial direction within the groove 79, in which further groove an O-ring 83 is arranged. The O-ring 83 acts on the second sliding element 77 with a force acting outwards in the radial direction.

[0081] The first sliding element 75 is designed here as a steel bushing and is connected in a positive-fitting manner to the housing 5. The steel bushing 75 is of solid design so that it counteracts the deformation of the housing 9 in the region of the front gripping region 27 due to its connection by means of the clamping band and the uneven circumferential forces that occur in the process to the desired extent.

[0082] The second sliding element 77 is designed in the present case as a grooved tubular ring made of plastic. Preferably, the second sliding element 77 is designed as a so-called Slydring®. Due to the selected material pairing of the first sliding element 75 and the second sliding element 77, good sliding properties are achieved, which enable the sliding elements 75 and 77 to be displaced relative to each other, which displacement occurs during operation, in particular in the longitudinal direction Z. The interaction of the O-ring 83 and the second sliding element 77 allows the assembly 9 to rotate relative to the housing 5 in this area.

[0083] Figures 14 to 16 An alternative design of the front decoupling device 23 is shown as a decoupling device 85. The decoupling device 85 has a first sliding element 75 and a second sliding element 87, which is designed here as a coated, grooved steel spring ring. The steel spring ring 87 is guided in the groove 79 of the component 9 and is fixed in particular in the longitudinal direction Z. The steel spring ring 87 is bent in the longitudinal direction Z and lies in the groove 79 in the longitudinal direction Z with an end region and in the longitudinal direction Z on the first sliding element 75 in the central region.

[0084] With the central area, the second sliding element 87 abuts the first sliding element 75 and slides thereon in the longitudinal direction Z when the assembly 9 is displaced relative to the housing 5. In order to improve the sliding properties, the second sliding element 87 preferably has a sliding lacquer coating.

[0085] In the installed position, the steel spring ring 87 is pretensioned in the radial direction and the radial stiffness can be set via the thickness of the disk.

[0086] Fig.17 An alternative embodiment of the second sliding element 89 is shown, in which in the present case there are a plurality of recesses 90 circumferentially in both end regions. By means of the number and arrangement of the recesses, the radial stiffness of the second sliding element 89 can be easily adjusted to the desired degree.

[0087] exist Figures 18 to 23 , a machine tool 91 of an alternative design is shown, which corresponds substantially to the machine tool 1. In the following, mainly the differences from the machine tool 1 are explained, and reference is made to the description of the machine tool 1 for other aspects.

[0088] The front decoupling device 23 has a decoupling device 93 having a first sliding element 95 fixed to the housing, a second sliding element 97 fixed to the assembly, and a third sliding element 99 .

[0089] The first sliding element 95 is designed as a steel bushing and is connected to the housing 5 in a positive-fit manner. Preferably, the first sliding element 95 is realized by a metal material. The first sliding element 95 has a circumferentially extending curved recess 101 in the central region in the longitudinal direction Z, which is arranged to cooperate with the third sliding element 99 and form an inner surface 102.

[0090] The second sliding element 97 is a component of the assembly 9 and has a hollow cylindrical region 103. The second sliding element 97 is preferably realized from a metal material.

[0091] In the present case, the third sliding element 99 has three parts 105, 107, 109, which in the present case are structurally substantially identical to one another. The parts 105, 107, 109 are each formed as a segment of a tube and have an inner surface 111 facing inwards in the radial direction relative to the longitudinal direction Z, which surface is a portion of a circular cross-section with a constant radius in the longitudinal direction Z. An outer surface 113 of the parts 105, 107, 109 facing outwards in the radial direction relative to the longitudinal direction Z is convex and has a curvature with a constant radius in the transverse direction X relative to the longitudinal direction Z. The third sliding element 99 is preferably realized in plastic.

[0092] The parts 105, 107, 109 each have a groove 115, 117 in a circumferential outer region, which has a width that increases in the longitudinal direction Z in the region of its end region in the circumferential direction toward the respective part 105, 107, 109. The parts 105, 107, 109 are each connectable to one another via a connecting element 119, which is each inserted into a groove 115, 117 of an adjacent part 105, 107, 109.

[0093] To assemble the decoupling device 93, first the first sliding element 95 is connected in a form-fitting manner to the housing 5. Subsequently, the three parts 105, 107, 109 of the third sliding element 99 are inserted into the curved recess 101 of the first sliding element 95 and connected to each other via the connecting element 119. Finally, the second sliding element 97 can be inserted into the interior of the assembly in the longitudinal direction Z.

[0094] The second sliding element 97 and the third sliding element 99 form a sliding pair which allows displacement of the component 9 in the region of the decoupling device 93 relative to the housing 5 in the longitudinal direction Z. Due to the selected material pairing, the friction is advantageously low.

[0095] The two circumferentially adjacent parts 105, 107, 109 of the third sliding element 99 are slightly spaced apart from each other in the circumferential direction. This distance between the second sliding element 97 and the third sliding element 99 enables the assembly 9 to rotate relative to the housing 5 about the transverse direction X and the vertical direction Y in the region of the decoupling device 93.

[0096] In the present case, the rear decoupling device 25 of the machine tool 91 has two first decoupling devices 121 , 123 , in the present case two second decoupling devices 125 , 127 , and a third decoupling device 129 .

[0097] In the present case, two first decoupling devices 121 and 123 are provided which are substantially mirror-symmetrical about a longitudinal center plane formed by the longitudinal direction Z and the vertical direction Y. The first decoupling device 121 assigned to the left is described below, which represents the first decoupling device 123 assigned to the right.

[0098] The first decoupling device 121 has a spring characteristic and / or a damping characteristic in the vertical direction Y of the machine tool 91. To this end, the first decoupling device 121 has two sliding elements 131, 133, which are spaced apart from each other in the vertical direction Y in the basic position, and two spring devices 135, 137 are arranged at a certain distance from each other in the longitudinal direction Z, which use a force acting in the vertical direction Y to press the sliding elements 131, 133 apart from each other.

[0099] The sliding elements 131 , 133 are displaceable relative to each other in the vertical direction Y against the spring force of the spring devices 135 , 137 and are rotatable relative to each other about the transverse direction X.

[0100] The sliding elements 131 , 133 each have a wedge-shaped surface 140 , pointing in the longitudinal direction Z, in their end region.

[0101] A bearing 139 connected to the assembly 9 is provided, each bearing having an angular profile 141, 143 spaced apart from one another in the longitudinal direction Z. It can be provided that the sliding elements 131, 133, for example the lower sliding element 131 in the vertical direction Y, are fixedly connected to the assembly 9. It can also be provided that both sliding elements 131, 133 are loosely connected to the bearing 139.

[0102] The angled contours 141 and 143 arranged in the end region interact here respectively with the wedge surface 140 of the first sliding element 131 and the wedge surface 140 of the second sliding element 133 and limit the maximum distance between the sliding elements 131, 133 in the vertical direction Y. The spring devices 135, 137 are realized in such a way that the sliding elements 131, 133 in the vertical direction Y which have the maximum spacing in the vertical direction Y are loaded with a force acting outwards in the vertical direction Y.

[0103] A guide 145 fixed to the housing is provided, which has a guide channel 147 pointing substantially in the longitudinal direction Z. The guide 145 is preferably realized in a metal material. The guide channel 147 has an extension in the vertical direction Y which substantially corresponds to the maximum extension of the surface of the sliding elements 131, 133 pointing outward in the vertical direction Y. Thus, the assembly 9 is guided relative to the housing 5 substantially in the longitudinal direction Z in the region of the second decoupling device 121. The guide channel 147 is designed such that it prevents or greatly limits the movement of the sliding elements 131, 133 relative to the guide 145 in the transverse direction X.

[0104] The angular contours 141 , 143 are designed here in such a way that during operation, by the movement of the assembly 9 relative to the housing 5 and by the interaction with the guide 145 , the movement transfer of the sliding elements 131 , 133 to one another is not hindered to the desired extent.

[0105] In the present case, two second decoupling devices 125 and 127 are provided which are substantially mirror-symmetrical about a longitudinal center plane formed by the longitudinal direction Z and the vertical direction Y. The second decoupling device 125 assigned to the left is described below, which represents the second decoupling device 127 assigned to the right.

[0106] The second decoupling device 125 has spring and / or damping properties in the transverse direction X of the machine tool.

[0107] The second decoupling device 125 has a displacement element 151 which, in the present case, has a pin-shaped region 153 and a substantially plate-shaped end region 155 . In the end region facing away from the plate-shaped end region 155 , the displacement element 151 has a shoulder 159 .

[0108] The pin-shaped region 153 has an axis 157 which extends approximately in the transverse direction X. On the circumferential side of the pin-shaped region 153, a hollow cylindrical decoupling element 149 is arranged directly on the pin-shaped region 153. The decoupling element 149 is arranged in the longitudinal direction of the axis 157 between the plate-shaped end region 155 and the shoulder 159 and is preferably prestressed in the longitudinal direction of the axis 157.

[0109] In the area of ​​the shoulder 159 , the decoupling element 149 protrudes outwardly beyond the shoulder in the radial direction of the axis 157 and interacts in this area with a bearing 161 fixed to the component, in the present case in the radial direction of the axis 157 and in the direction of the axis 157 .

[0110] The displacement element 151 interacts by means of the plate-shaped region 155 with a guide 163, which is metallic here and is arranged on the housing 5. The displacement element 151 and the guide 163 bear against one another in the transverse direction X, in particular due to the pretensioning of the decoupling element 149 acting in the direction of the axis 157 and thus in the transverse direction X. The interaction of the guide 163 with the displacement element 151 allows the component 9 to be displaced in the longitudinal direction Z and in the upward direction Y relative to the housing 5 by means of a sliding movement.

[0111] The third decoupling device 129 is designed substantially similarly to the second decoupling device 33 of the machine tool 1 and is designed as a spring device having spring and / or damping properties in the longitudinal direction Z.

[0112] Due to the interaction of the first decoupling devices 121, 123, the second decoupling devices 125, 127 and the third decoupling device 129, the component 9 can be displaced relative to the housing 5 in the longitudinal direction Z, in the transverse direction X and in the vertical direction Y in the area of ​​the rear decoupling device 25, wherein the movement of the component 9 relative to the housing 5 in the longitudinal direction Z, in the transverse direction X and in the vertical direction Y is particularly advantageously suppressed, so that the vibrations acting on the user during operation of the machine tool 91 are advantageously low.

[0113] In an alternative embodiment, it can be provided that the rear decoupling device 25 has only the first decoupling device 121, 123 and the third decoupling device 129, but not the second decoupling device 125, 127. This is advantageous in particular in the case of a machine tool 91 which has only a chiseling operation.

Claims

1. A machine tool (1, 91), in particular a hammer drill or a chisel hammer, comprising a housing (5) with a gripping area (7, 27) and a subassembly (9) comprising an impact mechanism (11) and a drive device (13), wherein the subassembly (9) is arranged substantially within the housing (5) and is arranged movably relative to the housing (5), wherein the center of gravity (15) of the subassembly (9) is arranged at a distance from an impact axis (19) defining a longitudinal direction (Z), wherein at least one front decoupling device (23) and at least one rear decoupling device (25) are arranged relative to the longitudinal axis (Z), wherein the decoupling devices (23, 25) are operatively connected to the housing (5) on the one hand and to the subassembly (9) on the other hand, characterized in that The at least one rear decoupling device (25) is designed such that the component (9) is movable relative to the housing (5) in all three spatial directions (X, Y, Z) and has spring and / or damping properties in all three spatial directions (X, Y, Z).

2. The machine tool according to claim 1, characterized in that The rear decoupling device (25) has a first decoupling device (31, 33; 53), which has spring characteristics and / or damping characteristics in the transverse direction (X) and the vertical direction (Y) of the machine tool (1), and a second decoupling device (33) is arranged, which has spring characteristics and / or damping characteristics in the longitudinal direction (Z).

3. The machine tool according to claim 2, characterized in that The first decoupling device (31, 33; 53) has a decoupling element (45) which extends circumferentially relative to an axis (49) of the first decoupling device (31; 85) extending in the longitudinal direction (Z).

4. The machine tool according to claim 3, characterized in that The decoupling element (45) has a cross section that is constant in a circumferential direction of the axis (49) or a cross section that varies in a circumferential direction of the axis (49).

5. The machine tool according to any one of claims 3 or 4, characterized in that: The decoupling element (45) is realized by an elastomer.

6. The machine tool according to any one of claims 2 to 5, characterized in that The first decoupling device (31, 33; 53) has an element (39; 75) operatively connected to the housing (5), the element being displaceable substantially in the longitudinal direction (Z) relative to an element (43; 87, 89) operatively connected to the assembly (9).

7. The machine tool according to claim 6, characterized in that The element (39) operatively connected to the housing (5) or the element (43) operatively connected to the assembly (9) is connected to the housing (5) or the assembly (9) under pretension by means of the decoupling element (45).

8. The machine tool according to any one of claims 2 to 7, characterized in that The first decoupling device (31, 33; 53) is arranged between the housing (5) and the component (9) in the region of a tool holder (16) facing away from the machine tool (1; 91).

9. The machine tool according to any one of claims 1 to 8, characterized in that: The rear decoupling device (25) has at least two first decoupling devices (31, 33), in particular substantially identically designed, which are each arranged at different positions between the housing (5) and the component (9).

10. The machine tool according to any one of claims 1 to 9, characterized in that The rear decoupling device (25) has at least one first decoupling device (121, 123), at least one second decoupling device (125, 127) and at least one third decoupling device (129), wherein the first decoupling device (121, 123) has spring characteristics and / or damping characteristics in the vertical direction (Y) of the machine tool (91), the second decoupling device (125, 127) has spring characteristics and / or damping characteristics in the lateral direction (X) of the machine tool (91), and the third decoupling device (129) has spring characteristics and / or damping characteristics in the longitudinal direction (Z).

11. The machine tool according to claim 10, characterized in that The first decoupling device (121, 123) has two sliding elements (131, 133), which are connected substantially in the vertical direction (Y) by means of at least one spring device (135, 137), in particular by means of at least two spring devices (135, 137), and are mounted in a guide (145) fixed to the housing.

12. The machine tool according to any one of claims 10 or 11, characterized in that The second decoupling device (125, 127) has a decoupling element (149) which is designed to rotate relative to an axis (157) extending in the transverse direction (X) and is arranged on an element (151) mounted opposite the component (9), the element (151) being guided on an element (145) fixed to the housing.

13. The machine tool according to any one of claims 1 to 12, characterized in that The front decoupling device (23) has a first sliding element (75) fixed to the housing and a second sliding element (77) interacting with the component (9), the second sliding element (77) interacting with the component (9) being pretensioned in the radial direction relative to the longitudinal direction (Z).

14. The machine tool according to any one of claims 1 to 13, characterized in that The front decoupling device (23) comprises a first sliding element (95) fixed to the housing, a second sliding element (97) fixed to the component, and a third sliding element (99), wherein the third sliding element (99) is displaceable substantially in the longitudinal direction (Z) relative to the second sliding element (97) fixed to the component, and wherein the first sliding element (95) has a curved sliding surface (102), which is designed to correspond to the sliding surface (113) of the third sliding element (99), and the component (9) is rotatable relative to the housing (5) substantially around the transverse direction (X) and / or around the vertical direction (Y) through the interaction between the sliding surface (102) of the first sliding element (95) and the sliding surface (113) of the third sliding element (99).

15. The machine tool according to any one of claims 1 to 14, characterized in that At least one supporting device (63, 65) is arranged between the assembly (9) and the housing (5) along the transverse direction (X), the supporting device (63, 65) comprising a supporting element (67) prestressed along the transverse direction (X).

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