Machine tool with offset linear guide

Abstract

The invention relates to a machine tool (1), in particular a hammer drill or chisel hammer, comprising a housing (5) having a rear grip region (7), comprising an assembly (9) comprising a striking mechanism device (11) and a drive device (13), wherein the assembly (9) is arranged at least partially within the housing (5) and is arranged movably relative to the housing (5), wherein the striking mechanism device (11) has a striking axis (19) defining a longitudinal direction (Z), and comprising a linear guide (61) with which the assembly (9) is mounted on the housing (5) such that it can move in the longitudinal direction (Z), wherein the housing (5) has a side grip securing region (62) which can be encircled by the strap of a side grip, wherein the striking axis (19) runs though the side grip securing region (62), characterised in that the linear guide (61) is arranged spaced apart from the side grip securing region (62) in the longitudinal direction (Z).

Description

[0001] Hilti Aktiengesellschaft in Schaan

[0002] Principality of Liechtenstein

[0003] Machine tool with offset linear guide

[0004] The invention relates to a machine tool, in particular a rotary hammer or chisel hammer according to the preamble of claim 1. Such a machine tool is equipped with a housing having a rear handle area, with an assembly comprising an impact mechanism and a drive unit, wherein the assembly is at least partially arranged within the housing and is movably arranged relative to the housing, wherein the impact mechanism has an impact axis defining a longitudinal direction, and with a linear guide by which the assembly is mounted on the housing so as to be displaceable in the longitudinal direction, wherein the housing has a side handle mounting area which can be enclosed by the tension band of a side handle, wherein the impact axis passes through the side handle mounting area.

[0005] EP4331774 A1 describes a machine tool, in particular a rotary hammer or chisel hammer, with a housing having a grip area and an assembly comprising a percussion mechanism and a drive mechanism, wherein the assembly is substantially arranged inside the housing and is movably arranged relative to the housing.

[0006] The object of the invention is to provide a machine tool with a movable assembly, wherein the machine tool has particularly good operating characteristics with particularly low design effort.

[0007] The problem is solved according to the invention by a machine tool having the features of claim 1. Preferred embodiments are specified in the dependent claims.

[0008] A machine tool according to the invention is characterized in that the linear guide is arranged at a longitudinal distance from the side-grip mounting area. Accordingly, a spatial and thus functional separation exists between the linear guide and the side-grip mounting area in the direction of the impact axis. It has been recognized that significant forces can occur in the side-grip mounting area when the clamping band is tightened, which can potentially lead to deformations of the encircled elements. The provided separation between the side-grip mounting area and the linear guide ensures, in a particularly simple design, that these effects do not interfere with the function of the linear guide. In particular, it counteracts an increase in friction on the linear guide with potentially increased vibration.

[0009] The grip area can, in particular, define a D-handle. The grip area is a rear grip area, i.e., located at the rear of the housing when viewed in the longitudinal direction Z. The side handle can, in particular, be a bar handle or a D-handle. The machine tool according to the invention can include the side handle, especially in the configuration in which it is attached to the side handle mounting area. The housing is preferably made of a plastic material.

[0010] The linear guide is a mechanical guide element that allows the assembly to be moved against the housing in a translational movement along a straight line, namely in the longitudinal direction.

[0011] Where the terms "radial", "axial", "rear", "front", and "circumferential direction" are used here, this may refer in particular to the axis of impact, unless otherwise specified in individual cases.

[0012] In particular, the linear guide is a (longitudinally speaking) front linear guide, i.e., it is located near a tool holder of the machine tool and away from the rear grip area of ​​the housing. Specifically, the linear guide can guide the assembly along the impact mechanism. The linear guide can act against the impact mechanism or against a part of an inner housing of the assembly surrounding the impact mechanism. Additionally, a rear linear guide can also be provided.

[0013] In particular, the linear guide can be offset longitudinally forward relative to the side handle mounting area. Preferably, a tool holder can be provided, and the linear guide, viewed longitudinally, can be arranged between the tool holder and the side handle mounting area. This can further reduce the design complexity and improve the operating characteristics even further. The tool holder is an integral part of the machine tool. It is operatively connected to the impact mechanism and serves to hold a tool extending in the direction of the impact axis, for example, a chisel or a drill bit.

[0014] According to a preferred embodiment, the linear guide can have a sliding sleeve arranged on the assembly, the radial outer surface of which the housing bears at least indirectly, and optionally also directly. This allows for the realization of a particularly useful linear guide in a very simple manner. The sliding sleeve can, for example, be made of a metal material, in particular steel, which can also be coated.

[0015] Furthermore, it is particularly preferred that the linear guide has an annular wiper lip arranged on the housing, which bears at least indirectly, and optionally directly, against the sliding sleeve, particularly on its radial outer surface. A self-cleaning function can be implemented in a particularly simple manner by means of such a wiper lip, which can reduce maintenance requirements. The annular wiper lip can also have one or more interruptions. The wiper lip can preferably be monolithically integrated with the housing.

[0016] In particular, it can be provided that the wiper lip projects forward from the housing (viewed in the longitudinal direction Z), i.e., that the wiper lip projects from the housing away from the grip area towards the tool holder. This allows for a particularly effective wiper lip with minimal design effort.

[0017] Another preferred embodiment of the invention consists in a stiffening sleeve being arranged on the housing, which stiffens the housing in the side-handle mounting area. This allows the resilience of the machine tool to be further improved in a particularly simple manner. The stiffening sleeve can, for example, be made of a metal material, in particular steel, which may also be coated. The stiffening sleeve is arranged in the side-handle mounting area. In particular, the stiffening sleeve is arranged longitudinally spaced from the sliding sleeve. The stiffening sleeve and the sliding sleeve are in particular arranged coaxially to each other and / or coaxially to the impact axis.

[0018] The invention is explained in more detail below with reference to preferred embodiments, which are schematically illustrated in the accompanying figures. Individual features of the embodiments described below can, in principle, be implemented individually or in any combination within the scope of the invention. The figures schematically show:

[0019] Fig. 1 shows a highly schematic side sectional view of a first embodiment of a machine tool in the rest position of the machine tool;

[0020] Fig. 2 shows a partially transparent detail view of the machine tool from Figure 1 in the front area of ​​the machine tool;

[0021] Fig. 3 is a perspective view of the machine tool from Figure 1 in the front area of ​​the machine tool.

[0022] The figures show a first embodiment of a machine tool 1, which in this case is designed as a rotary hammer or combination hammer, but in an alternative embodiment could also be designed, for example, as a chisel hammer or the like. The machine tool 1 is designed in this case as a cordless machine tool with a battery 3, but in an alternative embodiment it can also be designed for mains operation.

[0023] The machine tool 1 is designed here in an angled configuration and has a housing 5 with a D-shaped rear grip area 7. The housing 5, which can be made of one or more parts, is fixedly connected to the user-accessible grip area 7. In this case, the housing 5 is divided longitudinally Z and constructed in a so-called cup-shaped design. Alternatively, the housing 5 can also have two housing halves that can be joined together in the transverse direction X and be constructed in a so-called shell-shaped design.

[0024] Within the housing 5, an assembly 9 is arranged, comprising a conventionally designed striking mechanism 11 and a drive unit 13 designed as an electric motor, which is configured to drive the striking mechanism 11. The assembly 9 is L-shaped in this case.

[0025] The machine tool 1 has a tool holder 16 in a conventionally known manner, via which a tool 17, for example a chisel or the like, can be detachably connected to the assembly 9, in particular its impact mechanism 11. The assembly 9 enables chisel operation, whereby in chisel operation the tool 17 is moved back and forth in an oscillating motion in the direction of an impact axis 19. In hammer drilling operation, the tool 17 additionally performs a rotary motion about the impact axis 19.

[0026] Figure 1 shows a longitudinal direction Z, a vertical direction Y, and a transverse direction X. X, Y, and Z are axes of a Cartesian coordinate system and are mutually perpendicular. Without the application of an external force, the longitudinal direction Z coincides with the impact axis 19, which is defined by a central axis of the tool 17 held in the tool holder 16 or of the tool holder 16 itself. Without the application of an external force, the vertical direction Y is parallel to an output axis of the drive unit 13.

[0027] The assembly 9 can have a separate inner housing 21, in particular made of plastic, which in particular encloses the percussion device 11 and the drive device 13 or within which the percussion device 11 and the drive device 13 are in particular arranged almost completely or completely.

[0028] The machine tool also has a side handle 27, which forms a front grip area. The side handle 27 is connected to the housing 5 in a side handle mounting area 62 located near the tool holder 16. For the purpose of connecting it to the housing 5, the side handle 27 has a clamping band 28, which wraps around the housing 5 in the side handle mounting area 62. The clamping band 28 surrounds the impact axis 19, meaning that the impact axis 19 passes through the clamping band 28.

[0029] A stiffening sleeve 66, made of a metal material, preferably steel, is arranged on the housing 5, which consists essentially of plastic. This stiffening sleeve stiffens the housing 5 in the side handle mounting area 62. In the present embodiment, the stiffening sleeve 66 is arranged inside the housing 5. However, it can also be embedded in the housing 5 or arranged on the outside of the housing 5. The stiffening sleeve 66 and the tension band 28 overlap in the longitudinal direction Z, and the tension band 28 wraps around the stiffening sleeve 66.

[0030] In Figure 1, the side handle 27 extends essentially in the transverse direction X, and in Figures 2 and 3, it extends essentially in the vertical direction Y. The side handle is, in particular, infinitely adjustable in the circumferential direction relative to the longitudinal direction Z and can be arranged on the housing 5. The assembly 9 is movably mounted in the housing, in particular at least in the longitudinal direction Z. The assembly 9 is shown in the figures in one of its rest positions, in which the machine tool 1 is not in operation, or in which the assembly 9 is arranged in a forward end position relative to the housing in the longitudinal direction Z. During operation of the machine tool, vibrations arise from the interaction between a workpiece and the tool 17, which act mainly in the direction of the impact axis 19, i.e., in the longitudinal direction Z. These vibrations can be transmitted via a rear decoupling device 35 and the housing 5.The aim is to reduce or dampen as much as possible the vibrations or accelerations that arise in the area of ​​assembly 9 during the operation of the machine tool 1 by means of the rear decoupling device 35.

[0031] The rear decoupling device 35 exhibits spring and / or damping properties in the longitudinal direction Z (optionally, it can also act in the vertical direction Y and / or in the transverse direction X) and is designed here as a spring device with an axis of action essentially in the longitudinal direction Z. The decoupling device 35, designed here as a cylindrical helical spring, presses the assembly 9 into the front end position relative to the housing 5. Multiple decoupling devices 35 can also be provided, for example, two decoupling devices 35 spaced apart from each other in the transverse direction X. Alternatively or additionally, two decoupling devices 35 spaced apart from each other in the vertical direction Y can also be provided.

[0032] The machine tool 1 has a linear guide 61 by means of which the assembly 9, in particular its inner housing 21, is slidably mounted on the housing 5 in the longitudinal direction Z. The linear guide 61 has a sliding sleeve 65 arranged radially (relative to the impact axis 19) on the outside of the inner housing 21 of the assembly 9. This sliding sleeve 65 is preferably made of a metal material, in particular steel. The linear guide 61 further has an annular wiper lip 6, which is arranged on the housing 5 and bears against the radial (relative to the impact axis 19) outer side of the sliding sleeve 65. In the present embodiment, the wiper lip 6 is, by way of example, monolithic with the housing 5. In the present embodiment, the wiper lip 6 bears directly against the sliding sleeve 65. In an alternative embodiment, it could also bear indirectly against the sliding sleeve 65.The wiper lip 6 protrudes forward from the housing 5 (i.e., towards the tool holder 16).

[0033] The linear guide 61 and its components are, viewed in the longitudinal direction Z, offset forward relative to the side handle mounting area 62 and the stiffening sleeve 66. Thus, the linear guide 61 and its components are, viewed in the longitudinal direction Z, positioned closer to the tool holder 16 and / or further away from the handle area 7 than the side handle mounting area 62 and the stiffening sleeve 66.

[0034] The sliding sleeve 65 has a smaller diameter than the stiffening sleeve 66. The sliding sleeve 65 and / or the stiffening sleeve 66 are positioned coaxially to the impact axis 19.

Claims

PATENT CLAIMS 1. Machine tool (1), in particular a rotary hammer or chisel hammer, comprising a housing (5) having a rear handle area (7), an assembly (9) comprising an impact mechanism (11) and a drive unit (13), wherein the assembly (9) is at least partially arranged within the housing (5) and is movably arranged relative to the housing (5), wherein the impact mechanism (11) has an impact axis (19) defining a longitudinal direction (Z), and a linear guide (61) with which the assembly (9) is slidably mounted on the housing (5) in the longitudinal direction (Z), wherein the housing (5) has a side handle mounting area (62) which can be enclosed by the tension band (28) of a side handle (27), wherein the impact axis (19) passes through the side handle mounting area (62), characterized in that the linear guide (61) is spaced apart in the longitudinal direction (Z) from the Side handle mounting area (62) is arranged.

2. Machine tool according to claim 1, characterized in that the linear guide (61) is a front linear guide.

3. Machine tool according to one of the preceding claims, characterized in that a tool holder (16) is provided, and that the linear guide (61), viewed in the longitudinal direction (Z), is arranged between the tool holder (16) and the side grip mounting area (62).

4. Machine tool according to one of the preceding claims, characterized in that the linear guide (61) has a sliding sleeve (65) arranged on the assembly (9), on the radial outer side of which the housing (5) bears at least indirectly.

5. Machine tool according to claim 4, characterized in that the linear guide (61) has an annular wiper lip (6) which is arranged on the housing (5) and which bears at least indirectly against the sliding sleeve (65).

6. Machine tool according to claim 5, characterized in that the wiper lip (6) projects forward from the housing (5).

7. Machine tool according to one of the preceding claims, characterized in that a stiffening sleeve (66) is arranged on the housing (5), which stiffens the housing (5) in the side handle mounting area (62).

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