Hand-Held Power Tool

Abstract

A hand-held power tool, more particularly angle grinder, includes a cooling unit for cooling the hand-held power tool, a machine housing for receiving the cooling unit, and an air inlet opening for admitting an air flow. The hand-held power tool has a dust protection unit for reducing, especially without using a filter, dust particles in the air flow.

Claims

1. A hand-held power tool, comprising: a cooling unit configured to cool the hand-held power tool, a machine housing configured to receive the cooling unit, and an air inlet opening configured to admit an air flow, and a dust protection unit configured to reduce dust particles in the air flow.

2. The hand-held power tool according to claim 1, wherein the dust protection unit is further configured to divert the air flow.

3. The hand-held power tool according to claim 1, wherein the dust protection unit, in includes a dust protection element, that extends around the air inlet opening.

4. The hand-held power tool according to claim 1, characterized in that wherein the dust protection unit, includes a dust protection element, that is configured to form an air gap in at least one operating state so as to provide an air flow for the air inlet opening.

5. The hand-held power tool according to claim 1, wherein the dust protection unit comprises a spacer element that is configured to form an air gap for providing an air flow for the air inlet opening.

6. The hand-held power tool according to claim 1, wherein the dust protection unit is adjustable as a function of an operating state of the hand-held power tool.

7. The hand-held power tool according to claim 1, wherein: the machine housing comprises a handle area for gripping the hand-held power tool by way of an operator's hand, and the dust protection unit and/or the air inlet opening is arranged on the handle area.

8. The hand-held power tool according to claim 1, wherein the dust protection includes a dust protection element, that is formed from; an actuating element configured to switch the hand-held power tool on and off, or from a protective hood element configured to cover an accessory device.

9. The hand-held power tool according to claim 3, wherein the dust protection unit, wherein the dust protection element, is made of a material impermeable to air.

10. The hand-held power tool according to claim 1, further comprising a cooling channel which is configured to cool the hand-held power tool by way of the cooling unit, wherein the cooling channel is arranged at the air inlet opening.

11. The hand-held power tool according to claim 1, wherein: the air inlet opening, when viewed along a transverse axis, is arranged on a side of the machine housing facing a toolholder.

12. The hand-held power tool according to claim 1, wherein the machine housing comprises an air inlet opening and a further air inlet opening at a distance from the air inlet opening.

13. The hand-held power tool according to claim 12, further comprising a cooling channel which fluidically connects the air inlet opening to the further air inlet opening and which is configured to cool the hand-held power tool by way of the cooling unit.

14. The hand-held power tool according to claim 1, wherein the hand-held power tool is an angle grinder.

15. The hand-held power tool according to claim 1, wherein the dust protection unit is void of a filter.

16. The hand-held power tool according to claim 1, wherein the dust protection unit includes a dust protection element that is configured to form an air gap in every operating state so as to provide an air flow for the air inlet opening.

17. The hand-held power tool according to claim 8, wherein the accessory is a grinding wheel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Further advantages will become apparent from the description of the drawings hereinafter. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. The skilled person will advantageously also consider the features individually and merge them in order to provide further advantageous combinations. Shown are:

[0054] FIGS. 1 to 2 a side view of a hand-held power tool according to the present invention,

[0055] FIG. 3 a section through the hand-held power tool,

[0056] FIG. 4 a perspective view of the hand-held power tool,

[0057] FIG. 5 a section through a part of the hand-held power tool,

[0058] FIGS. 6a, 6b each show a further section through the hand-held power tool,

[0059] FIG. 7 a further view of the hand-held power tool,

[0060] FIG. 8 a section through a part of the hand-held power tool,

[0061] FIG. 9 a further section through a part of the hand-held power tool,

[0062] FIG. 10 a perspective view of the hand-held power tool,

[0063] FIG. 11, FIG. 12 a perspective view of each of a machine housing piece of the hand-held power tool, and

[0064] FIG. 13, 14 a development of a hand-held power tool.

[0065] In the following drawings, identical components are provided with identical reference signs.

[0066] FIG. 1 shows a hand-held power tool 11 designed as an angle grinder. To supply electrical energy to the hand-held power tool 11, the hand-held power tool 11 comprises a power cord. It is understood that the hand-held power tool 11 can also be operable by means of a battery. The hand-held power tool 11 is hand-held and hand-guided. In order to properly operate the hand-held power tool 11, an additional hand grip (not shown in more detail herein) is required and can be releasably connected to the hand-held power tool 11. The hand-held power tool 11 comprises a drive unit 13 having a drive shaft 15 movably supported about a drive axis 17 to an indirect drive of an accessory device designed as a grinding wheel not shown in more detail. To receive the accessory device, the hand-held power tool 11 comprises a toolholder 15 which is rotatably supported about an output axis 19. To transfer a movement from the drive unit 13 to the toolholder 15, the hand-held power tool 11 comprises a transmission unit 21 designed as an angle gear. To operate the hand-held power tool 11, an actuating element 23 is provided, which is provided to set the drive unit 13 into an operating state to drive the accessory device. The hand-held power tool 11 comprises a control unit or regulating unit 25 for controlling or regulating the drive unit 13.

[0067] The hand-held power tool 11 comprises a machine housing 27 which receives and surrounds the drive unit 13, the control unit or regulating unit 25, the transmission unit 21, and at least partially the toolholder 15.

[0068] The machine housing 27 of the hand-held power tool 11 is designed to be elongated and extends along a longitudinal axis L, which forms substantially a greatest extension of the hand-held power tool 11, and the longitudinal axis L coincides with the drive shaft 17 of the drive unit 13. The machine housing 27 is substantially cylindrical and has a circumferential area 29 extending around the longitudinal axis L. The machine housing 27 further comprises a front area 31 extending transversely, in particular perpendicularly, to a longitudinal axis L and to the circumferential area 29. The front area 31 delimits the machine housing 27 along the longitudinal axis L. The front area 31 is arranged on a side of the machine housing 27 facing away from the toolholder 15.

[0069] The hand-held power tool 11 comprises a cooling unit 33 for cooling the hand-held power tool 11. The cooling unit 33 is designed as a fan unit 33 and is designed to provide an air flow 35, 37 for cooling the drive unit 13 and the control unit or regulating unit 25. The cooling unit 33 is provided to direct the air flow 35, 37 through the machine housing 27 of the hand-held power tool 11. The cooling unit 33 is provided, on the one hand, to generate a negative pressure to form an air flow 35, 37, which enters the machine housing 27 through the air inlet opening 39, 41 and, on the other hand, to generate a positive pressure to guide the air flow 35, 37 through an air outlet opening out of the machine housing 27. A fan wheel, which is arranged on the drive shaft 15 of the drive unit 13 and is directly movable by means of the drive unit 13, can be considered as a fan unit 33. An impeller through which the flow can pass axially or radially can be considered as a fan wheel. To ensure that the drive unit 13 and the control unit or regulating unit 25 are sufficiently cooled, the cooling unit 33 is arranged between the drive unit 13 and the control unit, or between the regulating unit 25 and the transmission unit 21, and is surrounded by the machine housing 27.

[0070] An air inlet opening 39 is provided to generate an air flow 35 through the machine housing 27. The air inlet opening 39 extends through the machine housing 27 or through a wall of the machine housing 27. The air inlet opening 39 is designed as a wall passage in the machine housing 27. The air inlet opening 39 is provided for admitting an air flow 35. The drive unit 13 or the control unit or regulating unit 25 is arranged between the fan unit 33 and the air inlet opening 39.

[0071] The hand-held power tool 11 comprises a dust protection unit 45 for filter-free reduction of dust particles in an air flow 35 provided for the air inlet opening 39. The air flow 35 provided for the air inlet opening 39 is provided for passing through the air inlet opening 39.

[0072] The dust protection unit 45 is provided to divert the air flow 35, in particular to divert it such that the dust particles contained in the air flow 35 are separated, whereby the dust in the air flow 35 can be reduced. The dust protection unit 45 is designed as a dust separator. The dust separator is designed as an inertial or a deflection separator. By means of the dust protection unit 45, the air flow 35 is diverted so that dust particles located in the air flow 35 can be reduced. The dust protection unit 45 is arranged on the outside of the machine housing 27 and is provided to remove dust from the air flow 35, 37 even before entering the machine housing 27.

[0073] The dust protection unit 45 comprises a dust protection element 47. The dust protection element 47 is provided to cover or project from the air inlet opening 39 in an operating state. The dust protection element 47 overlaps the air inlet opening 39 in each operating condition. The air inlet opening 39 is arranged in the machine housing 27 below the dust protection element 47. Each extension of the dust protection element 47 is larger than each extension of the air inlet opening 39, so that the air inlet opening 39 is covered by at least 3 mm by the dust protection element 47 to all sides in each operating state (FIG. 7). The dust protection element 47 is provided such that the air flow 35 flows around it, at least in certain areas. The dust protection element 47 is at a distance from the air inlet opening 39 of at least 0.5 mm, e.g. about 0.6 mm, (actuating state, FIG. 2), and by no more than 11 mm, e.g. about 4.25 mm (release state, FIG. 1) in each operating state. The dust protection element 47 is at a first distance A1 of more than 4 mm and less than 8 mm in a release state opposite the air inlet opening 39 (FIGS. 6a, 9). The dust protection element 47 is at a second distance A2 of more than 1 mm and less than 2 mm in an actuating state opposite the air inlet opening 39 (FIG. 6b). The dust protection element 47 is at a first distance A1 of more than 1 mm and less than 2 mm opposite the air inlet opening 39. The dust protection element 47 surrounds the air inlet opening 39 in an operating state at a 360? angular range (FIG. 7). The dust protection element 47 extends in an operating state (actuating state) substantially parallel to the air inlet opening 39 and in a release state angled to the air inlet area 51.

[0074] The dust protection element 47 extends around the air inlet opening 39 and surrounds the air inlet opening 39 in an operating state by at least 330?. An, in particular each, extension of the dust protection element 47 along the longitudinal axis L is greater than an, in particular each, extension of the air inlet opening 39 along the longitudinal axis L. An, in particular each, extension of the dust protection element 47 transverse to the longitudinal axis L is greater than an, in particular each, extension of the air inlet opening 39, 41 transverse to the longitudinal axis L. The dust protection element 47 is in an operating state (actuating state) directly adjacent and arranged above the air inlet opening 39 (FIG. 6b).

[0075] The dust protection unit 45 is provided to form an air gap 57 in each operating state for providing an air flow 35 for the air inlet opening 39 (FIG. 2, FIG. 6). The air gap 57 is formed by the dust protection element 47 and the machine housing 27. The air gap 57 surrounds the air inlet opening 39 and comprises an air gap area which is larger than the air inlet area 51 of the air inlet opening 39, in particular all air inlet openings 39. The air gap 57 substantially completely surrounds the air inlet opening 39, 41. The air gap 57 can have an extension that is greater than an extension of the air inlet opening 39.

[0076] The machine housing 27 comprises a recess 61, which is provided for receiving the dust protection element 47. The recess 61 is formed by an elevation 63 of the machine housing 27. The elevation 63 extends around the dust protection element 47. The elevation 63 surrounds the dust protection element 47 at least in one operating state. The elevation 63 is at a distance from the dust protection element 47. As a result, an air flow 35 can flow between the machine housing 27 and the dust protection element 47. The recess 61 or the elevation 63 of the machine housing 27s forms the dust protection unit 45 together with the dust protection element 47.

[0077] The dust protection element 47 is arranged in an operating state between the air inlet opening 39 and the cooling channel 71 (section, FIG. 6). The dust protection element 47 is arranged in a release state transverse, in particular perpendicular, to the longitudinal axis L when viewed from above the air inlet opening 39, 41. The dust protection element 47 is arranged in an operating state transverse, in particular perpendicular, to the longitudinal axis L when viewed below the air inlet opening 39, 41 (FIG. 6). The dust protection element 47 is at a distance x in a release state with respect to the machine housing 27 (FIG. 6a). The dust protection element 47 is at a distance x In an operating state with respect to the machine housing 27, which becomes negative with respect to the distance in the release state (FIG. 6b). In the operating state, the air flow 35 is redirected more strongly than in the release state. The dust protection element 47 forms a bottom dead center in a release state and a top dead center in an operating state. In the release state, the dust protection element 47 is at a greater distance from the machine housing 27, as in an operating state.

[0078] The dust protection element 47 is at a distance from the air inlet opening 39 in one, in particular in each, operating state. The dust protection element 47 covers the air inlet opening 39 in the, in particular in each, operating state.

[0079] The dust protection unit 45 comprises a spacer element 65, which is provided to form the air gap 57 for providing an air flow 35 for the air inlet opening 39 (FIG. 8). The spacer element 65 is arranged on the machine housing 27. Alternatively or additionally, the spacer element 65 can be arranged on the dust protection element 47, in particular an unlocking unit of the dust protection element 47 (not described in more detail). The spacer element 65 is provided to keep the dust protection element 47 at a distance from the air inlet opening 39 or the machine housing 27 in an operating state. The spacer element 65 is arranged at a distance from the air inlet opening 39 and is provided to keep the dust protection element 47 at a distance from the air inlet opening 39 in an operating state such that an air flow 35 can pass between the dust protection element 47 and the machine housing 27, through the air inlet opening 39. The spacer element 65 limits a movement of the dust protection element 47 and forms a minimum distance of the dust protection element 47 from the machine housing 27. The spacer element 65 is designed as an elevation 63 and receives a spring element. The spring element is provided to return the dust protection element 47 from an operating state to a release state. The spacer element 65 forms a stop for the dust protection element 47 and the machine housing 27.

[0080] In one embodiment (not shown in more detail), the dust protection unit 45, in particular the dust protection element 47, can project into the air inlet opening 39 in an operating state.

[0081] In one embodiment (not shown in more detail), the dust protection unit 45, in particular the dust protection element 47, can delimit the air inlet opening 39.

[0082] The dust protection element 47 is adjustable as a function of an operating state. The dust protection element 47 is designed such that the dust particles in the air flow 35 can be reduced as a function of an operating state of the hand-held power tool 11. The dust protection element 47 adjusts an air gap 57 as a function of an operating state of the hand-held power tool 11. The dust particles in the air flow 35 can be reduced in an operating state (between bottom and top dead center) than in a further operating state (top dead center, as shown in FIG. 6b). A concentration of dust particles can be reduced as a function of an/the air gap 57. In an operating state (between bottom and top dead center), the air gap 57 is large enough that the air flow 357 can be deflected more weakly. In a further operating state (FIG. 6), the air gap 57 is small enough that the air flow 35 can be deflected more strongly.

[0083] The machine housing 27 comprises a handle area 67 for gripping by the operator's hand. The dust protection unit 45, in particular the dust protection element 47, and the air inlet opening 39 is arranged on the handle area 67. The handle area 67 is provided in an operating state to be gripped the machine housing 27 by the operator's hand. The dust protection element 47 is pivotally supported relative to the machine housing 27 about a pivot axis. The pivot axis is arranged on the machine housing 27 or on the handle area 67 of the machine housing 27.

[0084] The dust protection element 47 is designed as an actuating element 23 for turning on/off the hand-held power tool 11 or the drive unit 13 of the hand-held power tool 11.

[0085] Alternatively or additionally, the dust protection element 47 is designed as a protective hood element for covering an accessory device, in particular a grinding wheel (FIGS. 13, 14). The air inlet opening 39 is thereby arranged below the protective hood element 71. The protective hood member 71 is provided to cover the air outlet opening. The dust protection element 47 designed as a protective hood element 71 is designed to be substantially similar to the dust protection element 47 designed as the actuating element 23. However, in this case, the protective hood element 71 is at a nearly constant distance from the air inlet opening 39, 41. The protective hood member 71 is rotatably supported about the output axis 19 relative to the machine housing 27.

[0086] The actuating element 23 is designed as an actuating latch and is arranged on the handle area 67. The actuating element 23 extends along the longitudinal axis L and extends up to 70% opposite the handle area 67 along the longitudinal axis L. The actuating element 23 is provided to actuate or switch the drive motor of the hand-held power tool 11 on and off.

[0087] The air inlet opening 39 is arranged at the circumferential area 29 below the dust protection element 47. The dust protection element 47 is impermeable to air. The dust protection element 47 is made of a plastic material. The dust protection element 47 is formed at least in an area surrounding the air inlet opening 39 without passages or recesses.

[0088] The hand-held power tool 11 comprises a cooling channel 71, which is provided for cooling the hand-held power tool 11 by means of the cooling unit 33. The cooling channel 71 is arranged at the air inlet opening 39 and adjoins the air inlet opening 39. The cooling channel 71 is fluidically connected to the air inlet opening 39 such that the air flow 35 passes through the air inlet opening 39 into the cooling channel 71. The cooling channel 71 is formed substantially parallel to the air inlet opening 39 and extends along the longitudinal axis L of the hand-held power tool 11. The cooling channel 71 extends substantially parallel to the control unit or regulating unit 25.

[0089] The machine housing 27 comprises a further air inlet opening 41 at a distance from the air inlet opening 39. It is understood that the machine housing 27 of the hand-held power tool 11 can comprise a single number or plurality of air inlet openings 39 and/or further air inlet openings 41. In the present case, the machine housing 27 comprises four air inlet openings 39 (FIG. 4) and two further air inlet openings 41. The four air inlet openings 39 are arranged on a handle area 67 of the machine housing 27 and covered by the actuating element 23. The two further air inlet openings 41 are arranged on a front area 31 of the hand-held power tool 11.

[0090] The cooling channel 71 is provided to fluidically connect the air inlet opening 39 to the further air inlet opening 41. The cooling channel 71 is provided to cool the drive unit 13 and/or the control unit or regulating unit 25 by means of the cooling unit 33. The cooling channel 71 is substantially closed and has a cross-section perpendicular to a longitudinal axis L of the hand-held power tool 11, which is substantially closed along the longitudinal axis L.

[0091] The cooling channel 71 is formed from two housing portions 75, 77. The cooling channel 71 is formed from a first housing portion 75 and a second housing portion 77. The first housing portion 75 and the second housing portion 77 are releasably connectable to each other. The first housing portion 75 is provided to receive the drive unit 13 and the control unit or regulating unit 25. The second housing portion 77 can receive and substantially surround the first housing portion 75. The second housing portion 75 is pot-shaped and is inverted over the first housing portion 75 in a mounting process. The cooling channel 71 is designed to be double-walled, at least in sections. A first wall can be formed by the first housing portion 75 and a second wall can be formed by the second housing portion 77. An air flow 35 of the air inlet opening 39 and an air flow 37 of the further air inlet opening 41 open into the same cooling channel 71, thereby improving an air routing of the two air flows 35, 37 by the hand-held power tool 11. The air flow 37 of the further air inlet opening 41 can be provided for cooling the control unit or regulating unit 25 and/or the drive unit 13. The air flow 35 of the air inlet opening 39 can be provided to cool the drive unit 13. The air flow 35 of the air inlet opening 39 can be provided to cool the air flow 37 of the further air inlet opening 41.

[0092] The air inlet opening 39 and the further air inlet opening 41 are arranged substantially along the longitudinal axis L on a side facing away from the toolholder 15 in a rear area of the machine housing 27. The air inlet opening 39 extends substantially transversely, in particular perpendicularly, relative to the further air inlet opening 41. The air inlet openings 39, 41 or the air inlet openings 51, 53 are delimited by the machine housing 27. The air inlet opening 39 and the further air inlet opening 41 each comprise an air inlet area 51, 53. The air inlet area 51 of the air inlet opening 39 and the air inlet area 53 of the further air inlet opening 41 are aligned transversely, in particular perpendicular to each other. The air inlet opening 39 or an area normal of the air inlet area 51 is aligned substantially transversely, in particular perpendicularly, with the longitudinal axis L. The further air inlet opening 41 or another area normal of the air inlet area 53 is substantially aligned along the longitudinal axis L. By means of the air inlet opening 39, an air flow 35 can be drawn in substantially transversely, in particular perpendicularly, to the longitudinal axis L and by means of the further air inlet opening 41, an air flow 37 can be drawn in substantially along the longitudinal axis L.

[0093] The air inlet opening 39 and the further air inlet opening 41 are arranged substantially transversely, in particular perpendicularly, on a side of the machine housing 27 facing the toolholder 15 when viewed from the longitudinal axis L. The air inlet opening 39 and the further air inlet opening 41 are arranged below the drive shaft 17.

[0094] The hand-held power tool 11 comprises an actuating element 23, which is arranged substantially transversely, in particular perpendicularly, when viewed from the longitudinal axis L on a side of the machine housing 27 facing the toolholder 15. The actuating element 23 is arranged below the drive shaft 17 on the machine housing 27. The actuating element 23 is movably supported about an axis of movement and opposite the machine housing 27. The actuating element 23 comprises a first end and a second end. The actuating element 23 is rotatably connected to the machine housing 27 at the first end. The actuating element 23 comprises a second end. The second end forms a free end, in particular protruding from the machine housing 27. The first end is at a greater distance from the toolholder 15 than the second end.

[0095] The actuating element 23, in particular an extension of the actuating element 23, is angled relative to the machine housing 27 in a release state (FIG. 1) and arranged substantially parallel in an actuating state (FIG. 2). The second end of the actuating element 23 is at a further distance from the machine housing 27 in a release state (FIG. 1; FIG. 6a), as in an actuating state (FIG. 2, FIG. 6b).

[0096] The air inlet opening 39 is arranged along the longitudinal axis L when viewed between the cooling unit 33 and the further air inlet opening 41 and extends along the longitudinal axis L. The air inlet opening 39 is designed to be elongated and extends substantially parallel to the cooling channel 71. The air inlet openings 39 extend parallel to each other and have partially different lengths (FIG. 4, FIG. 7).

[0097] The machine housing 27 comprises a housing recess 81 in which the further air inlet opening 39, 41 is arranged (FIGS. 11, 12). The housing recess 81 is arranged in a side of the hand-held power tool 11 facing away from the toolholder 15. The housing recess 81 is arranged on the front area 31 of the machine housing 27. The housing recess 81 delimits the machine housing 27, in particular along and transversely, in particular perpendicularly, to the longitudinal axis L. The housing recess 81 extends from the front area 31 to the circumferential area or handle area 67. The housing recess 81 is delimited by a sidewall 83, which is delimited by a recess of the housing recess 81. The housing recess 81 is substantially L-shaped in a section through the hand-held power tool 11 (FIGS. 11, 12). The housing recess 81 comprises a longitudinal portion 87 and a transverse portion 89 extending transversely, in particular perpendicular, to the longitudinal portion 87. The longitudinal portion 87 is arranged at the circumferential area 29 and the transverse portion 89 is arranged at the front area 31. The further air inlet opening 41 is arranged in the transverse portion 89. The longitudinal portion 87 and the transverse portion 89 are connected together to form an air chamber.