This application claims priority under 35 U.S.C. § 119 to patent application no. DE 10 2016 210 853.0, filed on Jun. 17, 2016 in Germany, the disclosure of which is incorporated herein by reference in its entirety.
The disclosure relates to a hand-held power tool with a cooling unit.
Compact, high-performance hand-held power tools require optimum cooling of typical heat sources, such as the motor or the electronics, for maximum performance.
The cooling of the hand-held power tool is realized, as a rule, by means of a fan which sits on the motor shaft and sucks cooling air into the housing of the hand-held power tool via air intake openings. In this case, the cooling air is run in as direct a manner as possible past all components which provide the heat sources.
As hand-held power tools are frequently used in rough environments, it is possible that the cooling air may be contaminated with different metal particles, such as, for example, mineral or metallic dusts and fibers. Said particles are sucked in with the cooling air, as a result of which the particles may be deposited in the hand-held power tool, which, in turn, can result in impairment of the hand-held power tool.
DE 10 347 943 A1, as an example, describes a hand-held power tool which comprises a cooling device which comprises, at least in portions thereof, a cooling channel which is closed substantially in relation to an interior of the housing.
The object to provide a hand-held power tool which comprises a particularly efficient cooling unit is produced from the prior art.
The disclosure proceeds from a hand-held power tool, in particular an angle-grinding machine, including a housing, wherein a motor which is assigned to the drive train of the hand-held power tool, a cooling unit which is realized for the purpose of cooling the motor, and electronics are arranged in the housing, wherein a first housing part of the housing, in particular a motor housing, of the hand-held power tool comprises at least one air channel. It is proposed that the air channel is realized integrally with the first housing part, wherein a cooling air flow is conductible from an air intake opening of the housing directly to the motor via the air channel.
In an advantageous manner, the cooling air necessary for cooling the motor can be run past upstream components via the at least one air channel such that turbulence in the cooling air is prevented. The turbulence would otherwise result in dust being deposited, culminating in the free airflow cross sections necessary for the cooling being blocked and consequently preventing the motor cooling and possibly the cooling of other components.
The hand-held power tool is, in particular, a portable hand-held power tool which is able to be transported by an operator. The hand-held power tool comprises, in particular, a weight which is less than 40 kg, in a preferred manner less than 10 kg and in a particularly preferred manner less than 7 kg. The hand-held power tool is realized in a particularly preferred manner as an angle-grinding machine. However, it is also conceivable for the hand-held power tool to comprise a different design which appears sensible to the person skilled in the art, such as, for example, a design as a hammer drill and/or chisel hammer, as a drill, as a reciprocating saw, as a jigsaw, as a hedge trimmer, etc.
The housing of the hand-held power tool can be a single-part or multi-part housing which is realized for the purpose of receiving components of the hand-held power tool, such as, for example, a motor, in particular an electric motor, a transmission, the electronics, etc. In particular, the housing of the hand-held power tool is an exterior housing, the exterior housing also being able to include housing parts which are arranged in the interior of the housing. In an advantageous manner, the housing includes at least one housing part which can be designed in a pot-like manner or rather in the manner of a hollow cylinder or with the housing in the manner of a half shell. In an advantageous manner, the housing of the hand-held power tool comprises at least one motor housing in which the motor is arranged, and one handle housing. The handle housing can be realized in a stem-shaped manner, gun-shaped manner or pot-shaped manner. The handle housing is provided, in particular, for the purpose of providing on its outside surface a handle region which is realized so that the hand-held power tool is able to be held by a user.
The motor of the hand-held power tool can be realized as an electronically commutated electric motor and is provided for the purpose of driving an insertion tool. The commutation is effected in the case of electronically commutated electric motors by means of electronics. As an alternative to this, it is also conceivable for the hand-held power tool to comprise an electric brush motor where the commutation of the motor is realized via carbon brushes.
In an advantageous manner, the cooling unit comprises a fan element which is realized for the purpose of generating a cooling air flow. The fan element generates negative pressure in the housing of the hand-held power tool, as a result of which air is able to be sucked into the housing of the hand-held power tool via at least one air intake opening of the housing of the hand-held power tool. In an advantageous manner, the fan element is situated in the direction of flow of the cooling air flow downstream of the motor of the hand-held power tool. As an alternative to this, it is also conceivable for the fan element to be situated upstream of the motor in the direction of flow.
The electronics of the hand-held power tool can comprise a switching element, a mains connection, cabling, plugs and/or an actuator. The switching element is realized, in particular, for the purpose of switching the hand-held power tool on and off. The mains connection is realized for the purpose of supplying the hand-held power tool with power. The actuator can be realized as a component which is actuatable by the operator of the hand-held power tool. In particular, the actuator is mounted on the hand-held power tool so as to be movable. The actuator is realized for the purpose of adjusting at least one operating function, such as, for example, the rotational speed of the insertion tool.
An air channel which is realized integrally with a housing part is to be understood, in particular, as an air channel which is realized with a housing part as a component. In an advantageous manner, a cooling air flow is conductible directly to the motor in such a manner from an air intake opening of the housing of the hand-held power tool that the first component of the hand-held power tool which is acted upon inside the housing by the cooling air flow is the motor. In particular, the first component of the hand-held power tool which is cooled by the cooling air flow is the motor. In a particularly advantageous manner, no turbulence elements are arranged along the air channel. A turbulence element is to be understood, in this case, in particular, as a component of the hand-held power tool or a structural element of the housing of the hand-held power tool which results in turbulence of the cooling air flow.
The air channel can be realized in a closed manner with an air inlet opening and an air outlet opening. A closed air channel is to be understood, in particular, as the air channel comprising a wall which is substantially closed. The air channel is surrounded, in particular, on all sides. The air channel can comprise, for example, four side walls and a substantially rectangular cross section. However, a different geometric design of the cross section such as, for example, a round one is also conceivable. In particular, a side wall of the air channel can also be realized at least in part as an exterior wall of the housing. A closed wall is realized, in this case, without a gap in the circumferential direction between the air inlet opening and the air outlet opening. A substantially closed wall can comprise, in portions along the longitudinal extension of the air channel, a gap which is caused, for example, by a material transition. In an advantageous manner, up to 50% of the wall, in a particularly advantageous manner up to 75% or up to 100% is realized in a closed manner. The closed cooling channel is realized advantageously without turbulence elements and without gaps at which deposits are able to be formed.
At least one second housing part of the housing, in particular a housing cover, can comprise a second air channel, wherein at least one air channel of the first housing part, one air channel of the second housing part and a further air channel of the first housing part are arranged in the circumferential direction of the hand-held power tool. Efficient motor cooling can be realized in an advantageous manner as a result of a plurality of cooling channels.
The air channels of the first and of the second housing part can be arranged in such a manner that an anti-rotation device of the housing parts with respect to one another is provided. The anti-rotation device can act, in this case, in one direction of rotation, advantageously in both directions of rotation. In particular, at least one air channel of the first housing part acts upon at least one air channel of the second housing part in such a manner that a rotation of the second housing part is blocked at least in part in the circumferential direction. This can be realized, for example, as a result of the wall of an air channel of the first housing part abutting against the wall of an air channel of the second housing part. In particular, the walls abut against one another substantially along their longitudinal extension. It is also conceivable for the wall of the air channel to comprise outwardly protruding projections which act upon the wall of a further air channel. The rigidity of the housing of the hand-held power tool is significantly increased in an advantageous manner as a result of said design.
One housing part can be realized as a socketed cover, wherein the socketed cover comprises, in particular, at least one air channel. The socketed cover is advantageously arranged on a housing-side end of the hand-held power tool and is realized for the purpose of fastening a cable support sleeve on the hand-held power tool. A mains cable for the power supply of the hand-held power tool can be run via the cable support sleeve into the interior of the housing of the hand-held power tool. The socketed cover can additionally comprise an additional air intake opening which is provided for cooling the electronics. So that the housing of the hand-held power tool comprises sufficient air inlets, the socketed cover can be realized in a correspondingly large manner and can replace part regions of the housing cover. It is also conceivable for the socketed cover to consist of two or more housing parts.
The air intake openings can be arranged on an end-face end and/or on the side of the housing of the hand-held power tool. In particular, the end-face end is arranged on the rear end region of the hand-held power tool, the mains connection or a rechargeable battery interface being arranged on the rear end region of the hand-held power tool. In an advantageous manner, the air intake openings are arranged on the side of the housing on the rear end region of the hand-held power tool. In an advantageous manner, arranging the air intake openings on an end-face end and/or on the side of the housing of the hand-held power tool ensures that the operator of the hand-held power tool does not cover the air intake openings during use.
As an alternative to this, it is also conceivable for the end-side end to be arranged on a front end region of the hand-held power tool. In particular, the air intake openings can also be arranged on a gear head of an angle-grinding machine.
The air channel can comprise a recess, wherein a cooling body of the electronics is arranged in such a manner in the recess that the cooling body of the electronics forms at least in part at least one wall of the air channel. The cooling body of the electronics is realized, in particular, for the purpose of cooling the electronics. In an advantageous manner, the cooling body is arranged in such a manner in the recess of the air channel that it replaces the wall of the air channel in the recess. As a result, cooling of the electronics can be achieved in an advantageous manner without any significant reduction in the performance of the cooling of the motor.
The air channel can be realized at least in portions along the direction of flow of the cooling air as a cooling body of the electronics. In particular, the wall of the air channel is interrupted along the longitudinal extension, the wall of the cooling channel being replaced by the cooling body in the interruption in such a manner that the cooling body replaces the wall of the air channel along the entire circumferential direction. Advantageously, a particularly high performance of the cooling of the electronics can be realized as a result.
The electronics can be arranged on a carrier component, wherein the carrier component comprises at least one air channel. The carrier component can be produced, as an example, from a plastics material and can be realized so as to be pluggable onto a housing part.
The carrier component can be realized as a cooling body, in particular produced from a heat-conducting material, in an advantageous manner from a heat-conducting plastics material. As a result of said measure, the cooling air can be conducted directly to the motor in an advantageous manner without generating turbulence, the electronics being passively cooled at the same time.
Further advantages are produced from the following description of the drawings. Exemplary embodiments of the disclosure are shown in the drawings. The drawing, the description and the claims include numerous features in combination. The person skilled in the art will also look expediently at the features individually and form them into sensible further combinations. The drawings are as follows:
The motor housing 30 includes, as an example, two portions. The first portion of the motor housing 30 is realized in the manner of a hollow cylinder. In particular, an electric motor 32 is arranged in the first portion of the motor housing 30. The first portion of the motor housing 30 is loosely connected to the gear head 20 on a first connecting region 31. A fan element (not shown), which is realized for the purpose of generating a cooling air flow 5 for cooling the electric motor 32, is arranged on the motor-housing-side in the first connecting region 31 of the motor housing 30. The electric motor 32 includes a motor shaft which is coupled with the output spindle 26 by means of a crown wheel. The motor shaft extends along the axial axis 1 of the hand-held power tool 10. In particular, the rotational axis of the motor shaft corresponds to the axial axis 1 of the hand-held power tool 10. In the second connecting region 39 of the motor housing 30, the outside contour of the motor housing 30 merges into the outside contour of the handle housing 40. The handle housing 40 is realized in a pot-shaped manner. The handle housing 40 comprises air intake openings 110, through which the cooling air is able to enter into the housing 12 of the hand-held power tool 10, on the end-face end of the hand-held power tool 10. Another socketed cover 50, which comprises air intake openings 112, 114 and a screw receiving opening 116, is arranged in addition on the end-face end of the hand-held power tool 10. The handle housing 40 can be slid open by means of the second portion of the motor housing 30. The socketed cover 50 is fitted onto the handle housing 40. The handle housing 40 is connected to the motor housing 30 and to the socketed cover 50 by means of a screw 118, the counter thread for the screw 118 being arranged in the motor housing 30. In the connected state, a cable support sleeve 52, which is realized for the purpose of conducting a mains cable 54 into the hand-held power tool, is mounted between the handle housing 40 and the socketed cover 50. The second portion of the motor housing 30 is realized as a continuation which is encased by the handle housing 40. The second portion of the motor housing 30 is provided for the bearing arrangement or receiving of hand-held power tool components, in particular, the electronics 42. The electronics 42 include, as an example, a setting wheel 46 which is provided for adjusting the speed of the insertion tool, at least one electric contact element 48 which is provided for the electric connection between a switching element 49 and the drive train of the hand-held power tool 10, a shift linkage 45, a push button of the switching element 49 being actuatable via the shift linkage 45 when the operating switch 41 is actuated, and at least one mains connection 47 which is realized for the purpose of connecting the mains cable 54 to the electronics 42 in an electrical manner. The electronics 42 are arranged at least in part in a carrier component 44 which is realized so as to be detachably fastenable on the motor housing 30.
The hand-held power tool 10 is shown in the form of a mains-operated hand-held power tool which comprises the mains cable 54 for the power supply on the rear end 51 of the hand-held power tool 10. However, it is also conceivable for the power supply to be realized by means of a rechargeable battery pack, the rechargeable battery pack being connectable mechanically and electrically to the hand-held power tool via a rechargeable battery pack interface. A rechargeable battery pack is to be understood, in this case, as one or several battery cells which are connected together and are arranged in a housing. The housing of the rechargeable battery pack, in this case, comprises a rechargeable battery pack interface on its outside surface.
The air intakes 110, 112, 114 of the hand-held power tool 10 are distributed, as an example, over two housing parts 40, 50. The air intakes 110, which are arranged, in particular, in the vicinity of the socket receiving means, are realized, as an example, as air inlet openings 102 of the air channels 200 of the handle housing 40. In an advantageous manner, the cooling air flow 5 can be conducted directly into an air channel 200. The handle housing 40 and the air channel 200 which are assigned to the handle housing 40 are shown in perspective in
It is also conceivable, as shown in
As shown in
As an alternative to this, the air channel 100f can comprise a recess 101f, through which the cooling body 122f of the electronics 42 projects at least in part into the air channel 100f, as shown in
To increase the performance of the cooling of the electronics, the recess 101g can also be arranged in such a manner in the wall of the air channel 100g that the wing 123g of the cooling body 122g projects into the air channel 100g at a spacing from the wall of the air channel 100g, as shown in
In a further alternative embodiment, the air channels 100i can be realized integrally with the carrier component 44i (shown in
Number | Date | Country | Kind |
---|---|---|---|
10 2016 210 853 | Jun 2016 | DE | national |
Number | Name | Date | Kind |
---|---|---|---|
7597157 | Stierle | Oct 2009 | B2 |
8113922 | Esenwein | Feb 2012 | B2 |
20120184191 | Schulze | Jul 2012 | A1 |
Number | Date | Country |
---|---|---|
103 47 943 | May 2005 | DE |
Number | Date | Country | |
---|---|---|---|
20170361416 A1 | Dec 2017 | US |