Machine tool with a partitioning device

Abstract

The invention relates to a machine tool (1), in particular a drill hammer or chisel hammer, comprising a housing (5), which has a handle region (7, 27), and comprising an assembly (9), which comprises a striker device (11) and a drive device (13). The assembly (9) is arranged substantially within the housing (5) and is arranged so as to be movable relative to the housing (5). The center of gravity (15) of the assembly (9) is arranged at a distance to a striking axis (19). A partitioning device (87) is provided in order to limit an airflow between the assembly (9) and the housing (5), wherein the partitioning device (87) is attached to the assembly (9) and to the housing (5) and surrounds the assembly (9) circumferentially in the vertical direction (Y) of the machine tool (1).

Description

[0001] Machine tool with a sealing device

[0002] The present invention relates to a machine tool, in particular a drilling and / or chisel hammer, according to the type defined in more detail in the preamble of patent claim 1.

[0003] Machine tools, particularly rotary hammers and / or chisel hammers, are known in practice, in which a housing comprising a percussion mechanism and a drive unit is vibration-decoupled from an electronics unit and a battery interface unit. To prevent dust from entering the area containing the electronics, a uniaxially acting air barrier, for example in the form of a rubber sleeve, with a line of action in the longitudinal direction of the machine tool, is known.

[0004] DE 10 2020 216 538 A1 discloses a rotary hammer and / or chisel hammer comprising an outer housing and an inner housing. The inner housing is arranged within the outer housing, wherein the inner housing comprises a drive unit and a percussion unit. A vibration damping unit with a vibration damping element is provided for damping vibrations occurring during operation, by means of which a main handle connected to the outer housing is decoupled from the inner housing. The inner housing is mounted rotatably relative to the outer housing about a rotation axis arranged in the region of an instantaneous center of the percussion unit.

[0005] In such an embodiment, the provision of such a single-axis air barrier is disadvantageous since it only compensates for vibrations in the longitudinal direction and is also arranged in a lower area of ​​the machine tool, which is unfavorable in terms of installation space.

[0006] It is an object of the present invention to provide a machine tool, in particular a hammer drill or chisel hammer, in a machine tool with an assembly mounted movably relative to a housing, to achieve a space-saving seal between the assembly and the housing when the assembly moves relative to the housing in different spatial directions.

[0007] The object is achieved by the subject matter of independent claim 1. Further advantageous embodiments of the invention can be found in the corresponding subclaims. A machine tool, in particular a hammer drill or chisel hammer, is provided with a housing having a handle area and an assembly comprising a percussion mechanism and a drive device. The assembly is arranged substantially within the housing and is movable relative to the housing, with a center of gravity of the assembly being arranged at a distance from a percussion axis.

[0008] According to the invention, it is proposed that a partitioning device is provided in order to restrict and in particular substantially completely prevent an air flow between the assembly and the housing, wherein the partitioning device is connected to the assembly and to the housing and surrounds the assembly in a circumferential manner with respect to a vertical direction of the machine tool.

[0009] With a machine tool designed according to the invention, the proposed positioning and design of the partitioning device achieves a space-saving seal between the assembly and the housing when the assembly moves relative to the housing with large deflections in the longitudinal direction and, in particular, compared to smaller deflections in the vertical and / or transverse direction of the machine tool.

[0010] Due to the inventive arrangement of the sealing device circumferentially relative to the vertical direction, the sealing device can, in addition to compensating for movements of the assembly relative to the housing in the longitudinal direction, advantageously also cope with large movements of the assembly relative to the housing in a vertical direction and / or a transverse direction and can thereby reliably seal between the assembly and the housing.

[0011] A machine tool designed according to the invention has the advantage that air circulation in the area of ​​an intake and exhaust area of ​​the drive device and also electrical connections of the drive device and the electrical system are not negatively influenced by the partitioning device and a maximum cross-section for cooling air is available for the drive device.

[0012] Furthermore, the arrangement of the partitioning device according to the invention makes it possible to achieve favorable cooling of a stator in a simple manner by means of a cooling system that can be adjusted essentially symmetrically to a vertical axis.

[0013] By arranging the shielding device circumferentially with respect to the vertical direction of the machine tool, a lower area of ​​the machine tool (in the vertical direction) is free of the shielding device, so that, for example, electrical connections and / or a cable harness and / or a dust extraction system can be easily arranged in this area. A simple coupling of the shielding device to the housing and the assembly is achieved if the shielding device is permanently connected to the housing with a first area and permanently connected to the assembly with a second area.

[0014] In an advantageous embodiment of the invention, the sealing device comprises a flexible element and a dimensionally stable element. The flexible element allows for the desired sealing effect to be achieved, whereas the dimensionally stable element allows for a simple connection of the sealing device to the housing with the appropriate geometry.

[0015] In an advantageous embodiment of the invention, the flexible element has at least two regions extending substantially vertically and connected to each other longitudinally. Such a design of the partitioning device allows for large movements of the assembly relative to the housing in the longitudinal direction while simultaneously allowing movement in the transverse and vertical directions.

[0016] The partitioning device preferably has a U-shaped cross-sectional area. Depending on the dimensions, the movement of the assembly relative to the housing can be easily adjusted and adapted to the available installation space. The U-shaped area can be designed to be open both vertically upwards and downwards.

[0017] A favorable connection of the sealing device to the assembly and / or the housing is achieved if the sealing device is connected to the assembly and / or the housing via a form fit and / or material fit.

[0018] In an advantageous embodiment of a machine tool according to the invention, the partitioning device engages with the first region and / or second region in a recess or groove of the housing or the assembly, in particular in the longitudinal direction of the machine tool.

[0019] Alternatively or additionally, it can be provided that the sealing device encompasses an element of the housing or the assembly with the first region and / or the second region.

[0020] In an advantageous embodiment of the invention, the flexible element encompasses the dimensionally stable element in the circumferential direction and vertical direction. This creates a simple connection between the elements, reliably preventing the passage of air in this area. In an advantageous embodiment of a machine tool according to the invention, the flexible element is made of an elastomer. Preferably, the flexible element is a membrane, in particular made of an elastomeric material.

[0021] In an advantageous embodiment of the invention, the dimensionally stable element is made of a plastic. This makes it easy to achieve the desired stability. In principle, other materials, such as metallic materials, can also be used.

[0022] In an advantageous embodiment of a machine tool according to the invention, the partitioning device is designed such that it allows a movement of the assembly relative to the housing in the longitudinal direction of greater than 0.8 mm, in particular greater than 1.0 mm.

[0023] In an advantageous embodiment of a machine tool according to the invention, the sealing device is in a neutral or unbiased position when the assembly is in a position approximately central between two end positions with respect to the housing in the longitudinal direction. In this way, movements of the assembly relative to the housing, both toward the maximum deflection position and toward the minimum deflection position, can be easily compensated for, and the sealing device reliably seals between the assembly and the housing in all operating conditions.

[0024] Further advantages will become apparent from the following description of the figures. Various embodiments of the present invention are illustrated in the figures. The figures, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0025] They show:

[0026] Fig. 1 is a simplified side sectional view of a power tool designed as a hammer drill, with an outer housing and an assembly arranged in the housing, comprising a percussion mechanism and a drive device, wherein the assembly is displaceable relative to the housing by means of a front decoupling device and a rear decoupling device, wherein a partition device is provided for sealing between the assembly and the housing, and wherein the assembly is shown in a front end position relative to the housing without the application of external force; Fig. 2 is a representation of the power tool corresponding to Fig. 1, wherein the assembly is shown in a rear end position resting against a stop when an external force is applied;

[0027] Fig. 3 is a sectional view of the machine tool corresponding to Fig. 1 and Fig. 2, wherein the assembly is shown in a central position substantially centrally between the front end position and the rear end position;

[0028] Fig. 4 is a sectional view of the machine tool corresponding to Fig. 1 to Fig. 3, wherein the assembly is rotated about a transverse axis relative to the housing when an external force acts;

[0029] Fig. 5 is a sectional view of the machine tool according to Fig. 1;

[0030] Fig. 6 is a section of the machine tool according to Fig. 5, wherein the

[0031] The sealing device is shown in more detail;

[0032] Fig. 7 is a three-dimensional view of a section of the machine tool without the housing, showing the partitioning device in more detail;

[0033] Fig. 8 is a three-dimensional view of a section of the machine tool, showing a blow-out area and the partitioning device in more detail;

[0034] Fig. 9 is a sectional view of a section of the machine tool substantially corresponding to Fig. 7;

[0035] Fig. 10 a side view of the sealing device in isolation;

[0036] Fig. 11 is a plan view of the sealing device according to Fig. 10 in isolation;

[0037] Fig. 12 is a sectional view of the partition device according to Fig. 10 and Fig. 11;

[0038] Fig. 13 is a sectional view of the partition device according to Fig. 10 to Fig. 12, wherein the

[0039] Sealing device in a position with the assembly in an end position relative to the housing; and

[0040] Fig. 14 is a further sectional view of the partitioning device according to Fig. 10 to Fig. 13, wherein the partitioning device is in a position with the assembly in an end position relative to the housing. Exemplary embodiments:

[0041] Fig. 1 to Fig. 4 show a machine tool 1, which in the present case is designed as a hammer drill or combination hammer, but in an alternative embodiment can also be designed as a chisel hammer or the like.

[0042] The machine tool 1 is designed in the present case as a cordless machine tool with a battery 3, but can be provided for mains operation in an alternative embodiment.

[0043] The machine tool 1 is designed here in an angular construction and has a housing 5 with a rear handle area 7 in a D shape. The housing 5, which can be designed in one or more parts, is firmly connected to the handle area 7 that can be grasped by a user. In this case, the housing 5 is divided in the longitudinal direction Z and designed in a so-called pot construction. Alternatively, the housing 5 can also have, in particular, two housing halves that can be connected to one another in the transverse direction X and can be designed in a so-called shell construction.

[0044] Arranged within the housing 5 is a structural unit or assembly 9, which comprises a conventionally designed percussion mechanism 11 and a drive device 13 designed as an electric motor, which is designed to drive the percussion mechanism 11. In this case, the assembly 9 is L-shaped.

[0045] In this case, assembly 9 enables drilling or chiseling operation. In chiseling operation, tool 17 oscillates back and forth in the direction of the impact axis. In drilling or hammer drilling operation, the tool also performs a rotating movement around the impact axis.

[0046] Furthermore, an electronics unit 18 is visible, which is connected in a known manner via lines 20 to the drive device 13.

[0047] The machine tool 1 has, in a conventional manner, a tool holder 16, via which a tool 17, for example a chisel or the like, can be detachably and operatively connected to the structural unit 9.

[0048] The figures also show a longitudinal direction designated Z or Z-direction, a vertical direction designated Y or Y-direction, and a transverse direction designated X or X-direction. X, Y and Z are axes of a Cartesian coordinate system and are each perpendicular to one another. Without the action of an external force, the longitudinal direction Z is congruent with the impact axis, which is defined by a central axis of the tool or tool holder 16. In the embodiment shown, 15 indicates a center of gravity of the structural unit 9, which, with respect to the vertical direction Y, is arranged below the longitudinal direction Z in the illustrations shown and is thus spaced from the longitudinal direction Z.

[0049] The structural unit 9 can have a separate inner housing 21, which in particular comprises the percussion device 11 and the drive device 13 or within which the percussion device 11 and the drive device 13 are in particular almost completely arranged.

[0050] For example, Fig. 1 shows a front decoupling device 23 and a rear decoupling device 25, which can generally be designed with one decoupling device or multiple decoupling devices. In the illustrated embodiment, 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 an area facing away from the rear handle area 7.

[0051] In Fig. 1 to Fig. 4, a front gripping area 27 or lateral handle can be seen, which in this case can be releasably connected to the housing 5 in the area of ​​the front decoupling device 23, for example by means of a tensioning strap. In this case, the front gripping area 27 extends essentially in the transverse direction X, but can be arranged on the housing 5 in a manner that is continuously adjustable in the circumferential direction relative to the longitudinal direction Z.

[0052] The structural unit 9 is mounted relative to the housing 5 via both the front decoupling device 23 and the rear decoupling device 25, wherein the structural unit 9 is displaceable relative to the housing 5 both 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 displacement possibility s in the longitudinal direction Z is, for example, a maximum of approximately 10 mm, but can be up to 20 mm or more in other designs. The displacement possibility in the transverse direction X and in the vertical direction Y is essentially identical in the present case, wherein the displacement possibility s in the longitudinal direction Z is approximately 7 times as large as the displacement possibility in the transverse direction X and in the vertical direction Y.

[0053] To define a maximum travel 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 defining a defined end position of the structural unit 9 relative to the housing 5. The number and position of the stops 37 can generally be freely selected, with at least one, and in particular two, stops 37 being provided for each direction X, Y and Z on both sides of the structural unit 9. During drilling or chiseling operation of the machine tool, the interaction between a surface to be machined and the tool 17 creates vibrations or accelerations that 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 is not located on the impact axis or longitudinal axis Z, this also creates vibrations or accelerations transverse to the impact axis in the vertical direction Y.For example, unbalanced forces in the area of ​​the drive device 13 also cause vibrations or accelerations in the transverse direction X during operation of the machine tool 1.

[0054] During operation of the machine tool 1, vibrations and accelerations arise in the area of ​​the structural unit 9. These can be transmitted via the front decoupling device 23 and the rear decoupling device 25 to the housing 5, which has the front handle area 27 and the rear handle area 7. The aim of the decoupling devices 23, 25 is to reduce or dampen as much as possible the vibrations and accelerations that arise in the area of ​​the structural unit 9 during operation of the machine tool 1.

[0055] The assembly 9 is shown in Fig. 1 in the rest position, in which the machine tool 1 is not operating, or in which the assembly 9 is in the front end position in contact with the front stop 37a. In Fig. 2, the assembly 9 is shown in the rear end position and with the maximum deflection in the longitudinal direction Z, in which the assembly 9 is in contact with the stops 37b.

[0056] In the exemplary embodiment according to Fig. 1 to Fig. 4, a lateral stop 37d is shown assigned to a left side in the transverse direction X, with a correspondingly further lateral stop (not shown) being provided on a right side in the transverse direction X. The lateral stops 37d limit the movement path of the assembly 9 relative to the housing 5 in the transverse direction X.

[0057] In addition, an upper stop 37f and a lower stop 37g are provided, which limit a movement path of the assembly 9 relative to the housing 5 in the vertical direction Y.

[0058] In the following, the rear decoupling device 25 is first described in more detail.

[0059] The rear decoupling device 25 in the present case has a first decoupling device 31 and two second decoupling devices 33, 35.

[0060] The second decoupling devices 33, 35 of the rear decoupling device 25 have spring properties and / or damping properties in the longitudinal direction Z and are designed here as spring devices with an axis of action substantially in the longitudinal direction Z. The spring devices 33, 35, designed here as cylindrical helical springs, press the assembly 9 relative to the housing 5 in Fig. 1 into the front end position, in which the assembly 9 rests against the front stop 37a. In Fig. 2, the spring devices 33, 35 are shown in a maximally tensioned position. The spring devices 33, 35 assume this position when the assembly 9 is relative to the housing 5 in the rear end position, in which the assembly 9 rests against the rear stops 37b, 37c. In Fig.3, the assembly 9 is shown in a middle position relative to the housing 5, in which a distance of the assembly 9 in the longitudinal direction Z from the front stop 37a and from the rear stops 37b, 37c is substantially identical and amounts to approximately s / 2.

[0061] The spring devices 33, 35 are arranged spaced apart from one another in the vertical direction Y, with the spring device 33 being arranged in the region of the impact axis 19. The spring device 35 is arranged in the region of the drive device 13 between the assembly 9 and the housing 5.

[0062] In alternative embodiments, additional second spring devices may also be provided, wherein, for example, two spring devices 35 arranged spaced apart from one another in the transverse direction X may be provided. Alternatively or additionally, additional spring devices arranged spaced apart from one another in the vertical direction Y may also be provided.

[0063] In the embodiment according to Fig. 1 to Fig. 4, a single first decoupling device 31 is provided, which is arranged at any position between the assembly 9 and the housing 5. It is particularly advantageous if the distance between a decoupling device 29 of the front decoupling device 23 and the first decoupling device 31 in the longitudinal direction Z is as large as possible.

[0064] In alternative embodiments, a plurality of first decoupling devices 31 can also be provided, which are arranged spaced apart from one another, in particular in the vertical direction Y, between the assembly 9 and the housing 5.

[0065] Fig. 4 shows, in a greatly exaggerated manner, that the assembly 9 can rotate relative to the housing 5 about an axis running in the transverse direction X during operation of the machine tool 1. Furthermore, the assembly 9 can also rotate relative to the housing 5 about an axis running in the vertical direction Y and / or about an axis running in the longitudinal direction Z. The front decoupling device 23 and the rear decoupling device 25 are designed in such a way that they enable such rotations and, in particular, can also dampen vibrations or accelerations transmitted thereby.

[0066] Fig. 1 to Fig. 4 also show a further first decoupling device 36, which is arranged in a lower region of the machine tool 1 in the vertical direction Y between the assembly 9 and the housing 5. The further first decoupling device 36 is optional and can, if necessary, improve spring and / or damping properties.

[0067] In Fig. 5, the rear decoupling device 25 has a single first decoupling device 31.

[0068] The first decoupling device 31 has a first sliding element 39, which here is designed as a pin-shaped element with a central axis 49. The pin-shaped element 39, designed for example as a steel pin, is connected to the housing 5 in a form-fitting manner by means of a screw connection via a thread 41 arranged in the longitudinal direction Z in the rear end region. The first decoupling device 31 further has a second sliding element 43 which interacts with the first sliding element 39 and serves as a sliding partner therefor, which second sliding element 43 is designed as a sliding bushing in this case. The sliding bushing 43 interacts via a decoupling element 45 with a bearing block 47 fixed to the assembly. The bearing block 47 is connected to a gear housing of the assembly 9 via a form-fitting connection.

[0069] The decoupling element 45 is fixed here in the direction of the central axis 49 relative to the sliding bushing 43. For this purpose, the sliding bushing 43, which is preferably made of plastic, is preferably clipped into the decoupling element 45. In an outer region in the radial direction relative to the central axis 49, the decoupling element is fixed in the direction of the central axis 49 via a bushing 51 and the bearing block 47.

[0070] It can also be provided that the decoupling element 45 is glued to the sliding bush 43 and / or to the bearing block 47.

[0071] The decoupling element 45 is tubular here with a substantially constant wall thickness. In an alternative embodiment, the decoupling element 45 can have a varying wall thickness on the circumferential side relative to the central axis 49.

[0072] The decoupling element 45 is made of an elastomer. In the rest position of the assembly 9, the decoupling element 45 has a preload in the radial direction of the central axis 49 in order to achieve a desired radial stiffness in the transverse direction X and vertical direction Y. In the area of ​​the first decoupling device 31, rotation of the assembly 9 relative to the housing 5 is possible.

[0073] In addition to the embodiment shown in Fig. 6 with a first decoupling device 31, a further, substantially identically constructed first decoupling device can also be provided, which can be arranged in a lower region of the assembly 9 with respect to the vertical direction Y and in a rear region with respect to the longitudinal direction Z. In particular, such a further first decoupling device can be arranged in the region of the drive device 13.

[0074] Furthermore, the decoupling device 29 of the front decoupling apparatus 23 can be seen in Fig. 6. 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 substantially in the longitudinal direction Z relative to the assembly. The second sliding element 77 is prestressed in the radial direction with respect to the longitudinal direction Z. For this purpose, a further groove 81 is provided in the radial direction within the groove 79, in which an O-ring 83 is arranged. The O-ring 83 applies a force to the second sliding element 77 acting outwards in the radial direction.

[0075] The first sliding element 75 is designed here as a steel bushing and is positively connected to the housing 5. The steel bushing 75 is designed to be so solid that it counteracts, to the desired extent, a deformation of the housing 9 in the area of ​​the front handle section 27 by connecting it by means of a tensioning band and the resulting non-uniform circumferential forces.

[0076] The second sliding element 77 is designed here with a slotted tubular plastic ring. Preferably, the second sliding element 77 is designed as a so-called Slydring®. The selected material pairing of the first sliding element 75 and the second sliding element 77 achieves good sliding properties, which enables a displacement of the sliding elements 75 and 77 relative to one another during operation, particularly in the longitudinal direction Z. The interaction of the O-ring 83 and the second sliding element 77 enables rotation of the assembly 9 relative to the housing 5 in this area.

[0077] Fig. 5 also shows a partitioning device 87, by means of which a vacuum side of the machine tool 1 is sealed off from a pressure side of the machine tool 1 between the assembly 9 and the housing 5. The only open cross-section between the pressure side and the vacuum side is through a fan 89, which is provided for building up pressure on the pressure side. Fig. 9 shows that the partitioning device 87 seals off an air intake area 93, which represents a vacuum area, and an air outlet area 95, which represents a positive pressure area. This seal is ensured in all operating states of the machine tool 1 and thus when the assembly is in the front end position or in the rear end position or in an intermediate position therebetween relative to the housing 9.

[0078] In addition, the sealing device 87 also reliably seals between the housing 5 and the assembly 9 when the assembly 9 is rotated relative to the housing 5 about an axis running in the transverse direction X, vertical direction Y and / or longitudinal direction Z.

[0079] In the present case, the partition device 87 can be brought into engagement with a drive housing 91 of the drive device 13 from a lower side in the vertical direction Y, so that the partition device 87, in the assembled state, is connected to the drive housing 91 on a radially inner side. A lower region of the drive device 13 in the vertical direction Y is thus free for the arrangement of, for example, cable harnesses that are connected to an outer side of the drive housing 91.

[0080] The partition device 87 or air barrier shown in isolation in Fig. 10 to Fig. 12 comprises a flexible element 97 and a dimensionally stable element 99.

[0081] The flexible element 97 is preferably made of an elastomer and is designed, for example, as an elastomer membrane. In this case, the flexible element 97 has a U-shaped cross-section with two regions 101 and 103 extending essentially in the vertical direction Y, which are connected by a region 105 extending in the longitudinal direction Z. In this case, the U-shaped cross-section is open essentially upwards in the vertical direction Y. In an alternative embodiment, the U-shaped cross-section can also be open essentially downwards in the vertical direction Y.

[0082] The flexible element 97 is connected to the dimensionally stable element 99 via a positive and / or material connection, wherein the flexible element 97 is connected to the drive housing 91 by means of a positive connection. For this purpose, the flexible element 97 in the present case has a first region 109 connected to the region 101, which is designed, for example, as a circumferential nose, wherein the nose 109 can be brought into operative connection with a groove 113 of the drive housing 91.

[0083] The dimensionally stable element 99 is designed, for example, as a plastic frame, by means of which the partition device 87 can be secured to the housing 5. For this purpose, the housing 5 has, for example, a circumferential groove 107, particularly with respect to the vertical axis Y, into which the dimensionally stable element 99 can be inserted and fixed with a second region 111.

[0084] In order to connect the plate-shaped dimensionally stable element 99 to the flexible element 97, the flexible element 97 has a recess 115 pointing radially outwards with respect to the vertical direction Y, into which the dimensionally stable element 99 engages with an edge region.

[0085] In this case, the first region 109 is arranged higher in the vertical direction Y relative to the recess 115. This makes it possible, in particular, to compensate for a large displacement of the assembly 9 relative to the housing 5 in the longitudinal direction Z. In alternative embodiments, depending on the general conditions, the first region 109 and the recess 115 can also be located at approximately the same height in the vertical direction Y, or the first region 109 can be arranged lower than the recess 115.

[0086] In Fig. 6, the assembly 9 is shown in the middle position according to Fig. 3 relative to the housing 5. The flexible element 97 is in an undeformed and, in particular, non-tensioned position. This has the advantage that the flexible element 97 is not deformed to an undesirably large extent, is not exposed to undesirably large strains and stresses, and the sealing effect is not impaired, both when the assembly 9 is in the front end position and when it is in the rear end position relative to the housing 5.

[0087] In Fig. 13 and Fig. 14, for example, a deformation of the flexible element 97 is shown, which the flexible element 97 assumes when the assembly 9 is in the front end position relative to the housing 5.

Claims

Patent claims:

1. A machine tool (1), in particular a hammer drill or chisel hammer, comprising a housing (5) having a handle area (7, 27) and an assembly (9) comprising a percussion mechanism (11) and a drive device (13), wherein the assembly (9) is arranged substantially within the housing (5) and is arranged such that it can move relative to the housing (5), wherein a center of gravity (15) of the assembly (9) is arranged at a distance from an impact axis (19), characterized in that a partition device (87) is provided in order to restrict an air flow between the assembly (9) and the housing (5), wherein the partition device (87) is connected to the assembly (9) and to the housing (5) and surrounds the assembly (9) in a circumferential manner with respect to a vertical direction (Y) of the machine tool (1).

2. Machine tool according to claim 1, characterized in that the partitioning device (87) is connected to the housing in a first region (109) and to the assembly in a second region (111).

3. Machine tool according to claim 1 or 2, characterized in that the partitioning device (87) has a flexible element (97) and a dimensionally stable element (99).

4. Machine tool according to claim 3, characterized in that the flexible element (97) has at least two regions (101, 103) extending substantially in the vertical direction, which are connected to one another in the longitudinal direction (Z).

5. Machine tool according to one of the preceding claims, characterized in that the partitioning device (87) has a U-shaped region in cross section.

6. Machine tool according to one of the preceding claims, characterized in that the partitioning device (87) is connected to the assembly (9) and / or the housing (5) via a positive connection and / or material connection.

7. Machine tool according to one of claims 2 to 6, characterized in that the partition device (87) engages with the first region (109) and / or second region (111) in a recess (107, 113) of the housing (5) or the assembly (9).

8. Machine tool according to one of claims 2 to 7, characterized in that the flexible element (97) surrounds the dimensionally stable element (99) in the circumferential direction of the vertical direction (Y).

9. Machine tool according to one of claims 3 to 8, characterized in that the flexible element (97) is made of an elastomer.

10. Machine tool according to one of claims 3 to 9, characterized in that the dimensionally stable element (99) is made of a plastic 11. Machine tool according to one of the preceding claims, characterized in that the partitioning device (87) is designed such that it permits a movement of the assembly (9) relative to the housing (5) in the longitudinal direction (Z) of greater than 0.8 mm, in particular greater than 1.0 mm.

12. Machine tool according to one of the preceding claims, characterized in that the partitioning device (87) is in a neutral position when the assembly (9) is in a position approximately central between two end positions with respect to the housing (5) in relation to the longitudinal direction (Z).

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