Hand-held machine tool

Abstract

A hand-held power tool (100) is disclosed, comprising a housing (110), a drive unit (111), a percussion mechanism (122) driven by the drive unit (111), and a tool holder (150) for receiving a tool insert (140), wherein the tool holder (150) is at least partially driven by the percussion mechanism (122). It is proposed that the hand-held power tool (100) includes a spacer element (200) designed to distance the tool insert (140) from the housing (110).

Description

[0001] The present invention relates to a hand-held power tool according to the preamble of claim 1. State of the art

[0002] A hand-held power tool comprising a drive unit, a housing, a percussion mechanism and a tool holder is already known from the prior art. Disclosure of the invention

[0003] The present invention relates to a hand-held power tool comprising a housing, a drive unit, a percussion mechanism driven by the drive unit, and a tool holder for receiving an insert tool, wherein the tool holder is at least partially driven by the percussion mechanism. It is proposed that the hand-held power tool include a spacer element designed to keep the insert tool away from the housing.

[0004] The invention provides a handheld power tool in which the robustness of the tool holder is increased. The tool holder in handheld power tools is a common point of failure, particularly breakage, under high loads. Depending on the tool used, it can happen that the tool slips back and forth within the tool holder during operation. This results in suboptimal torque transmission from the impact mechanism and uneven loading of the tool holder. This can then lead to load peaks that, over time, cause defective or broken tool holders. The present invention solves this problem.

[0005] The hand-held power tool can be electrically powered. This electrically powered power tool can be either mains-powered or battery-powered. For example, the hand-held power tool can be a screwdriver, a drill / driver, an impact driver, a hammer, a rotary hammer, or an impact drill / driver.

[0006] The housing of the hand-held power tool is designed to at least partially accommodate the drive unit, the impact mechanism, and the tool holder. The housing can be designed as a shell housing with two half-shells.

[0007] The hand-held power tool includes a drive unit. The drive unit comprises a drive motor and a gearbox. The drive motor can be an electrically commutated drive motor. In particular, the drive motor can be designed as at least one electric motor. The gearbox can be designed as at least one planetary gearbox, which may, for example, be switchable. The drive motor is designed such that it can be operated via a hand switch. When the hand switch is operated by a user, the drive motor is switched on and the hand-held power tool is put into operation. If the hand switch is no longer operated by the user, the drive motor is switched off. Preferably, the drive motor is electronically controllable and / or regulated in such a way that reversing operation and setting a desired rotational speed are possible.In reversing mode, the drive motor can be switched between clockwise and counterclockwise rotation. To switch the drive motor in reversing mode, the hand-held power tool can have a direction-of-rotation switching element, in particular a direction-of-rotation switch.

[0008] The hand-held power tool features a percussion mechanism. During operation, the percussion mechanism generates high torque peaks to loosen or tighten fasteners, or to drill holes. The percussion mechanism can be connected to the drive motor via a gearbox. The percussion mechanism can be designed, for example, as a rotary percussion mechanism, a ratchet percussion mechanism, a rotary percussion mechanism, a V-groove percussion mechanism, or a hammer percussion mechanism. The gearbox and / or the percussion mechanism can have an intermediate shaft. For example, the intermediate shaft can accommodate planetary gears of the gearbox. Furthermore, the intermediate shaft can at least partially drive the percussion mechanism. The percussion mechanism can have a percussion housing and / or a percussion cover. Furthermore, the percussion mechanism can have at least one striker or hammer and at least one percussion spring.The striker and the striking mechanism spring can be arranged essentially within the striking mechanism housing. The striker comprises at least one striking cam. Two or three striking cams may be provided, for example. The striking mechanism spring can be designed, for example, as a coil spring, a barrel spring, a conical spring, a chimney spring, or a profile spring.

[0009] The hand-held power tool features a tool holder. The tool holder can be configured as an internal tool holder, such as a bit holder, and / or as an external tool holder, such as a socket holder. The tool holder can accommodate tools such as screwdriver bits, socket wrenches, or sockets, enabling a user to create screw connections between a fastener and a mounting bracket. The impact mechanism is designed to drive an output shaft. The output shaft is designed to drive the tool holder. The tool holder has at least one anvil cam at one end facing the impact mechanism and / or the drive unit. The impact mechanism's striker is designed to rotate the anvil cam circumferentially by means of the impact cam, thereby driving the tool holder.For example, the tool holder can have two or three anvil cams.

[0010] The power tool also includes a power supply, which is designed for battery operation using rechargeable batteries, in particular power tool battery packs, and / or for mains operation. In a preferred embodiment, the power supply is designed for battery operation. Within the scope of the present invention, a "power tool battery pack" is understood to be an assembly of at least one battery cell and a battery pack housing. The power tool battery pack is advantageously designed to supply power to commercially available battery-operated power tools. The at least one battery cell can, for example, be a lithium-ion battery cell with a nominal voltage of 3.6 V. By way of example, the power tool battery pack can comprise up to ten battery cells, although a different number of battery cells is also conceivable.Both the battery-powered version and the mains-powered version are sufficiently known to those skilled in the art, which is why the details of the power supply will not be discussed here.

[0011] The hand-held power tool may have a control unit, at least for controlling the drive unit. The control unit may be located in the housing, for example in a handle of the hand-held power tool or in the area of ​​a power supply interface.

[0012] The spacer element is designed to keep the tool apart from the housing. Specifically, the spacer element positions the tool so that, when connected to the tool holder, it remains separated from the housing and essentially does not touch it during operation of the power tool. The spacer element is exemplified as a spacer. It can be, for example, ring-shaped, disc-shaped, or plate-shaped.

[0013] In one embodiment of the hand-held power tool, the spacer element can be attached to the tool holder. The spacer element can be attached in such a way that, when the spacer element is in use, the tool holder remains essentially unobstructed. The spacer element can be connected to the tool holder, for example, by a positive and / or non-positive connection.

[0014] In one embodiment of the hand-held power tool, the spacer element has a receptacle for the tool holder. The receptacle for the tool holder can have an internal recess for the tool holder. The internal recess for the tool holder can have a shape corresponding to the tool holder. Arranging the spacer element on the tool holder by means of the internal recess of the spacer element enables optimal torque transmission from the tool holder to the tool.

[0015] In one embodiment of the hand-held power tool, the tool holder has a transition section, the receptacle for the spacer element of which can be arranged on the transition section. The spacer element receptacle is designed such that it accommodates the transition section. The spacer element receptacle and the transition section are designed to correspond to each other. The inner receptacle of the spacer element is designed to correspond to the transition section. The tool holder also has a torque transmission section or drive section. The torque transmission section is designed to transmit torque to the tool. The torque transmission section can be polygonal, such as rectangular. For example, the torque transmission section can be essentially cube-shaped.Furthermore, the tool holder can have a driven section. The driven section can terminate in the anvil cam. The driven section can, for example, be cylindrical. The driven section is designed to transmit a rotary motion received by the anvil cam to the transition section. The transition section can be arranged between the torque transmission section and the driven section.

[0016] In one embodiment of the hand-held power tool, the transition section has a radius in the range of 3 mm to 8 mm. The radius is optimized to increase the stability and robustness of the transition section. Preferably, the radius is formed in the range between 5 mm and 7 mm.

[0017] In one embodiment of the hand-held power tool, the receptacle for the spacer element has a polygonal section. This polygonal section is designed to correspond to the torque transmission section. The polygonal section allows the spacer element to engage with the tool holder, and in particular, at least partially with the torque transmission section, in a form-fitting manner. The polygonal section can be shaped, for example, as a cube, a hollow cube, a cuboid, or a hollow cuboid. The polygonal section can be oriented towards the tool holder or the tool insert.

[0018] In one embodiment of the hand-held power tool, the receptacle for the spacer element has a cylindrical section. This cylindrical section is designed to correspond to the output section. The cylindrical section allows the spacer element to engage with the tool holder in a form-fit manner. The cylindrical section can be oriented towards the drive unit.

[0019] In one embodiment of the hand-held power tool, the spacer element has a contact element designed to receive the tool holder. The contact element can, for example, be configured as a contact surface of the spacer element. The contact element can be oriented away from the drive unit when the tool holder is connected to the tool holder. The contact element can be connected to the spacer element. It is possible for the contact element and the spacer element to be formed as a single piece. The spacer element and the contact element can be made of an elastic material. Both the contact element and the spacer element can serve to dampen vibrations during operation of the hand-held power tool. The contact element can, for example, be disc-shaped or ring-shaped.

[0020] In one embodiment of the hand-held power tool, the spacer element can be arranged at a distance from the housing and / or a percussion mechanism housing on the tool holder. The spacer element can be arranged at such a distance on the tool holder that, during operation of the hand-held power tool, and in particular the tool holder, the spacer element leaves the housing and / or the percussion mechanism housing unaffected.

[0021] The invention also relates to the spacer element for the hand-held power tool described above according to one of claims 1 to 9. Brief description of the drawings

[0022] The invention is explained below with reference to preferred embodiments. The drawings below show: Fig. 1 a schematic view of a hand-held power tool according to the invention; Fig. 2a a side view of the hand-held power tool with a spacer element; Fig. 2b the side view of the hand-held power tool with the connected spacer element; Fig. 3 a section of a longitudinal section of a tool holder of the hand-held machine tool with the connected spacer element; Description of the exemplary implementations

[0023] Fig. 1 Figure 1 shows a hand-held power tool 100 according to the invention, which is designed as an exemplary cordless impact wrench 100. The hand-held power tool 100 comprises a tool holder 150. The hand-held power tool 100 has a housing 110 with a handle 126. The hand-held power tool 100 can be mechanically and electrically connected to a power supply for battery operation to provide an independent power supply, so that the hand-held power tool 100 is designed as a cordless hand-held power tool 100. A hand-held power tool battery pack 130 serves as the power supply. However, the present invention is not limited to cordless hand-held power tools, but can also be applied to mains-powered, i.e., mains-operated, hand-held power tools.

[0024] The housing 110 includes a drive unit 111. The drive unit 111 is arranged within the housing 110. The drive unit 111 comprises an electrically commutated drive motor 114, which is powered by the power tool battery pack 130, and a gearbox 118. The gearbox 118 is designed as at least a planetary gearbox. The drive motor 114 is designed such that it can be operated, for example, via a hand switch 128, allowing the drive motor 114 to be switched on and off. Advantageously, the drive motor 114 is electronically controllable and / or adjustable, enabling reversing operation and a desired rotational speed. For reversing operation, the power tool 100 has a direction-of-rotation switching element 121, which is designed as a direction-of-rotation switch.The direction-of-rotation switching element 121 is designed to switch the drive motor 114 between a clockwise and a counterclockwise direction of rotation. The design and operation of a suitable drive motor are well known to those skilled in the art, and therefore will not be discussed in detail here.

[0025] The housing 110 at least partially accommodates the drive motor 114, the gearbox 118, and the tool holder 150. Here, the housing 110 is designed as a shell housing with two half-shells 112.

[0026] The hand-held power tool 100, designed as a cordless impact wrench, comprises an impact mechanism 122, in particular a rotary impact mechanism 122, with an intermediate shaft 120. Both the rotary impact mechanism 122 and the intermediate shaft 120 are arranged in the housing 110. The rotary impact mechanism 122 comprises an impact mechanism housing 123, and the rotary impact mechanism 122 may also be arranged in another suitable housing, such as the gearbox housing 119. The rotary impact mechanism 122 comprises a striker and an impact mechanism spring, the striker and the impact mechanism spring being not shown in detail. The striker and the impact mechanism spring are arranged essentially within the impact mechanism housing 123. The striker has two impact cams, which are not shown in detail. The rotary impact mechanism 122 is designed to drive an output shaft 124. The hand-held machine tool 100 comprises a tool axis 102, wherein a rotational axis of the output shaft 124 forms the tool axis 102.The output shaft 124 is designed to drive the tool holder 150. The tool holder 150 is provided on the output shaft 124. Preferably, the tool holder 150 is integrally formed and / or formed on the output shaft 124. Preferably, the tool holder 150 is arranged in an axial direction 132 pointing away from the drive unit 111. The tool holder 150, or the output shaft 124, comprises two anvil cams 164 at one end facing the rotary impact mechanism 122 and / or the drive unit 111 (see also [reference]). Fig. 3 The striker of the rotary impact mechanism 122 is designed to rotate the anvil cams circumferentially by means of the impact cams, thereby driving the tool holder 150 or the output shaft 124. The tool holder 150 is designed here as an external tool holder 152, such as a socket holder. The tool holder 150 is designed to accommodate insert tools 140, such as socket wrenches or sockets.

[0027] The hand-held power tool 100 has a control unit 170, at least for controlling the drive unit 111, in particular the drive motor 114. The housing 110 at least partially accommodates the control unit 170.

[0028] Furthermore, the housing 110 includes a power supply holding device 160. The power supply holding device 160 accommodates the hand-held power tool battery pack 130 and forms a base 162 with a standing surface. The hand-held power tool battery pack 130 can be detached from the power supply holding device 160 without tools. The housing 110 also includes the handle 126 and the power supply holding device 160. The handle 126 can be gripped by the user. In one embodiment, the power supply holding device 160 is arranged on the handle 126. The hand-held power tool 100 can be set down using the base 162.

[0029] Fig. 2 shows a side view 300 of the hand-held power tool 100. This shows Fig. 2a The side view 300 with a spacer element 200. Fig. 2b Figure 300 shows the side view of the hand-held power tool 100 with the connected spacer element 200. The hand-held power tool 100 includes the spacer element 200. The spacer element is designed to distance the insert tool 140 from the housing. The spacer element 200 distances the insert tool 140 such that, when connected to the tool holder 150, the insert tool 140 is spaced from the housing 110 and does not substantially touch it, at least during operation of the hand-held power tool 100. For illustrative purposes, the spacer element 200 is shown here as an annular spacer. The spacer element 200 can be attached to the tool holder 150. The spacer element 200 can be connected to the tool holder 150 in a form-fitting manner. The spacer element 200 includes a receptacle 210 for the tool holder 150, wherein the receptacle 210 is designed as an internal receptacle 212 for the tool holder 150.The internal recess 212 for the tool holder 150 comprises a corresponding form to the tool holder 150.

[0030] The tool holder 150 comprises a transition section 230. The receptacle 210 of the spacer element 200 can be arranged on the transition section 230, the receptacle 210 of the spacer element 200 being shaped such that it accommodates the transition section 230. Furthermore, the receptacle 210 of the spacer element 200 and the transition section 230 are shaped correspondingly to each other. The tool holder 150 comprises a torque transmission section 240, or drive section. The torque transmission section 240 is designed to transmit torque to the tool 150. Here, the torque transmission section is polygonal, for example, rectangular, and essentially cube-shaped. The tool holder 150 includes a driven section 250. The driven section 250 terminates in the anvil cam 164, see also Fig. 3 Here, for example, the output section 250 is cylindrically shaped. The transition section 230 is arranged between the torque transmission section 240 and the output section 250. The transition section 240 has a radius 232 in the range of 3 mm to 8 mm.

[0031] The spacer element 200 comprises a contact element 220. The contact element 220 is designed to receive the insert tool 150, so that the insert tool 150 rests against the contact element 220 during operation of the hand-held power tool 100. Here, the contact element 220 is shown as a contact surface 222. The contact element 220 is arranged facing away from the drive unit 111 when the insert tool 140 is connected to the tool holder 150. The spacer element 200 forms the contact element 220, so that they are a single piece. The spacer element 200 and the contact element 220 are made of an elastic material. The contact element 220 is, for example, disc-shaped. The spacer element 200 can be arranged at a distance from the housing 110 and / or the impact mechanism housing 123 on the tool holder 150.

[0032] Fig. 3Figure 310 shows a section 310 of a longitudinal section of the tool holder of the hand-held power tool 100 with the connected spacer element 200. The receptacle 210 of the spacer element 200 comprises a polygonal section 214. The polygonal section 214 of the receptacle 210 of the spacer element 200 is polygonal in such a way that it is shaped correspondingly to the torque transmission section 240. In the connected state, the polygonal section 214 can at least partially engage with the torque transmission section 240 in a form-fitting manner. For example, the polygonal section 214 is shaped like a hollow cube and faces towards the tool holder 150 or the insert tool 140. The receptacle 210 of the spacer element 200 comprises a cylindrical section 216. The cylindrical section 216 of the receptacle 210 of the spacer element 200 is shaped in such a way that it corresponds to the output section 250.The cylindrical section 214 enables the spacer element 200 to bear against the output section 250 of the tool holder 150 in a form-fitting manner. Here, the cylindrical section 216 is shaped in the direction of the drive unit 111.

Claims

1. Hand-held power tool (100) comprising a housing (110), a drive unit (111), a percussion mechanism (122) driven by the drive unit (111) and a tool holder (150) for receiving an insert tool (140), wherein the tool holder (150) is at least partially driven by means of the percussion mechanism (122), characterized by a spacer element (200) designed to space the insert tool (140) away from the housing (110).

2. Hand-held power tool (100) according to claim 1, characterized by the fact that the spacer element (200) can be attached to the tool holder (150).

3. Hand-held power tool (100) according to claim 1 or 2, characterized by the fact that the spacer element (200) has a receptacle (210) for the tool holder (150).

4. Hand-held power tool (100) according to claim 3, characterized by the fact thatthe tool holder (150) has a transition section (230), wherein the holder (210) of the spacer element (200) can be arranged on the transition section (230).

5. Hand-held power tool (100) according to claim 4, characterized by the fact that the transition section (230) has a radius (232) in the range of 3 mm to 8 mm.

6. Hand-held power tool (100) according to one of claims 2 to 5, characterized by the fact that the inlet (210) of the spacer element (200) has a polygonal section (214).

7. Hand-held power tool (100) according to one of claims 2 to 6, characterized by the fact that the receptacle (210) of the spacer element (200) has a cylindrical section (216).

8. Hand-held power tool (100) according to one of the preceding claims, characterized by the fact that the spacer element (200) has a mounting element (220) which is designed to receive the insertion tool (140).

9. Hand-held power tool (100) according to one of the preceding claims, characterized by the fact that the spacer element (200) is spaced from the housing (110) and / or a percussion mechanism housing (123) can be arranged on the tool holder (150).

10. Spacer element (200) for a hand-held power tool (100) according to one of claims 1 to 9.

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