The invention relates to an open-circuit-ventilated hand-held power tool, in particular, powered by rechargeable batteries, comprising a housing base accommodating the electromotive drive components, and having air inlet openings supplying the electromotive drive components with a cooling air flow. In particular, the invention relates to hand-held power tools, in which the electromotive drive components comprise permanent magnets.
Hand-held power tools usually require air cooling, which is why air inlet openings are provided in the region of the electromotive drive, through which a cooling air flow is formed over the electromotive drive components. Especially in the case of hand-held power tools for metalworking, in particular, cutting and grinding, such as is performed using angle grinders, the problem arises that, with the cooling air flow, magnetizable dust penetrates into the interior of the hand-held power tools and is deposited on the electromotive components, in particular, on the permanent magnets of the electric motor and is near impossible to remove because of its magnetic adhesion. This can result in considerable damage to the electromotive drive components.
The object of this invention is to solve this problem in a simple and economically viable manner.
This task is inventively solved in a hand-held power tool of this type in that a filter element is provided in the area of the air inlet openings by means of which dust, especially magnetizable dust, can be kept away from the electromotive drive components, the filter element is retained by a filter retaining part that can be attached to the exterior of the housing base, the filter retaining part can be elastically deformed to such an extent that it is slightly deformed, especially expanded, when attached to the housing base, and engages behind or snaps into an element on the housing base.
By disposition of a filter element, in particular, a paper filter, particulate and, in particular, corrosive magnetizable dust can be retained.
In a further embodiment of the invention, the filter element or the filter retaining part is provided in such a way that the air inlet openings are essentially covered over their entire surface from outside by the filter element. This facilitates sealing toward the interior and ensures easier replacement of the filter element. To ensure an effective and powerful cooling air flow, the filter element must also be easy to clean or replace, which is simpler if the filter element is positioned on the exterior of the housing base.
According to a further embodiment of the invention, the filter retaining part on the housing base is pivotably attached to the exterior. This has the advantage of captive mounting of the filter retaining part on the housing base. The filter retaining part therefore forms a sort of holding means to hold the filter element in the region of the air inlet openings on the housing base.
Because the filter retaining part can be snapped onto the housing base and engages behind an element on the housing base, the filter retaining part can be simply and quickly mounted in its intended position on the housing base of the hand-held power tool, for example, when the filter element is replaced.
Because the filter retaining part can be elastically deformed, the snap-on operation can be performed simply. The filter retaining part is simply manually pressed into its intended position. The filter retaining part then slides around the contour of the housing base, wherein it, for example, expands slightly and then snaps into a stable position. To remove or open the filter retaining part, the user can slide the filter retaining part off again in the opposite direction by effecting slight elastic expansion.
In a further embodiment of the invention, the filter retaining part can be constituted as a shell shape with openings. The shell shape then largely matches the outer contour of the housing base. In this way, the filter retaining part can be very flat and be positioned compactly on the housing base of the hand-held power tool. In this case, it is even possible for the filter retaining part to be provided in the region intended for manual holding of the hand-held power tools.
According to a further embodiment of the invention, the filter retaining part, as seen in a longitudinal direction of the housing base of the hand-held power tool and in cross-section, is approximately constituted in the shape of a circular arc with a circumferential length of preferably a little more than 180° .
Further characteristics, details, and advantages can be derived from the appended claims and from the drawings and the following description of preferred embodiments of the inventive hand-held power tool. The drawings show
a),b) different perspective views of a first embodiment of the inventive hand-held power tool;
a-c) different perspective views of a second embodiment of the inventive hand-held power tool and
In the region of the section of the housing base 4 comprising the air inlet openings 10, a filter retaining part 12 is snapped onto the housing base 4 from below and outside in the direction of the arrow 14. The filter retaining part 12 is constituted in the shape of a half shell and adapted to the outer contour of the housing base 4 in this region. It also has elongated openings 16. A filter element 20, in the simplest case, a sheet of a paper filter, can be positioned against the inside 18 of the filter retaining part 12 facing the housing base 4. This paper filter element then covers the air inlet openings 10 in the housing base 4 from outside and retains, in particular, corrosive magnetizable dust.
Moreover, the filter retaining part 12 can also constitute the filter element or incorporate it as an integral component. For example, it is conceivable for the filter retaining part 12 to comprise a glued-on or molded-on plastic or metal sieve or similar filter component as an integral component in the region of its openings 16.
In this case, too, it proves advantageous if the filter retaining part 30 protrudes only a few millimeters beyond the exterior of the housing base 4 to avoid impeding handling of the hand-held power tool 2.
Number | Date | Country | Kind |
---|---|---|---|
10 2008 009 277.0 | Feb 2008 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP2009/000569 | 1/29/2009 | WO | 00 | 8/3/2010 |