AIR FILTER DEVICE FOR FILTERING THE INTAKE AIR OF A COMBUSTION ENGINE, IN PARTICULAR FOR A HAND-HELD SMALL TOOL

Abstract

An air filter device for filtering the intake air of a combustion engine of a hand-held small tool, in particular an angle grinder, with a pre-filter stage having at least one cyclone air filter and with a main filter stage arranged downstream, having a permeable filter body, characterized in that a pre-separation device for pre-separating contaminations in the intake air is installed upstream of the intake air in front of the cyclone air filter, wherein the pre-separation device is configured in such a way that separated contaminations can be removed from the outside of the small tool.

Claims

1. An air filter device for filtering the intake air of a combustion engine of a hand-held small tool, in particular an angle grinder, with a pre-filter stage comprising at least one cyclone air filter and with a main filter stage arranged downstream, comprising a permeable filter body, wherein a pre-separation device for pre-separating contaminations in the intake air is installed upstream of the intake air in front of the cyclone air filter, wherein the pre-separation device is configured in such a way that separated contaminations can be removed from the outside of the small tool.

2. The air filter device according to claim 1, wherein the pre-separation device is configured as a labyrinth filter with which the separation of the contaminations from the intake air is possible by means of at least one diversion of the intake air.

3. The air filter device according to claim 1, wherein the air filter device has a hood, wherein the labyrinth filter is arranged between the hood and the cyclone air filter.

4. The air filter device according to claim 1, wherein the cyclone air filter is mounted at or configured one-piece with a carrier, wherein the carrier has at least one wall element, which forms a first part of a labyrinth filter.

5. The air filter device according to claim 2, wherein the hood has at least one wall element, which forms a second part of the labyrinth filter.

6. The air filter device according to claim 5, wherein at least one wall element at the hood forms a moisture protection against water ingressing into the area between the hood and the cyclone filter.

7. The air filter device according to claim 1, wherein a dirt collection area is configured below the labyrinth filter.

8. The air filter device according to claim 7, wherein the dirt collection area is configured between the core and the hood.

9. The air filter device according to claim 7, wherein the hood has openings in the dirt collection area, which are configured for removing the contaminations collected in the dirt collection area.

10. The air filter device according to claim 1, wherein the labyrinth filter is configured to be removable from the hood at least with the wall elements mounted at the hood and/or from the carrier with the wall elements mounted at the carrier.

11. The air filter device according to claim 1, wherein the labyrinth filter is configured as a module that can be removed from the air filter device and in particular from the hood.

12. A handheld small tool with an air filter device for filtering the intake air of a combustion engine of the angle grinder, with a pre-filter stage comprising at least one cyclone air filter and with a main filter stage arranged downstream, comprising a permeable filter body, wherein a pre-separation device for pre-separating contaminations in the intake air is installed upstream of the intake air in front of the cyclone air filter, wherein the pre-separation device is configured in such a way that separated contaminations can be removed from the outside of the small tool.

Description

PREFERRED EMBODIMENT OF THE INVENTION

[0018] Further measures improving the invention are shown in more detail in the following together with the description of a preferred embodiment of the invention by means of the figures. The figures show the following:

[0019] FIG. 1 a general view of an angle grinder with an air filter device according to the invention

[0020] FIG. 2 a detailed view of the air filter device for filtering the intake air, wherein the hood of the angle grinder is shown in a sectional view

[0021] FIG. 3 a bottom view of the hood of the angle grinder and

[0022] FIG. 4 a view of the carrier of the angle grinder, at which two cyclone air filters and a device for receiving a filter body are configured.

[0023] FIG. 1 shows an angle grinder 100 as an example of a handheld small tool, which has an air filter device for filtering an intake air 1. The angle grinder 100 has a hood 13, which is configured to be removable from the remaining body of the device. In the hood 13, air inlet openings 20 are installed, through which the intake air 1 can pass.

[0024] FIG. 2 shows a sectional view through the hood 13 in arrangement at the body of the device, wherein the body of the device further comprises a core 14, which is shown in the view underneath the hood 13. If the intake air 1 enters through the air inlet openings 20, the intake air 1 reaches an area between the hood 13 and the carrier 14. At the carrier 14, cyclone air filters 10 are configured, wherein, due to the sectional view, a front cyclone air filter 10 is visible, into which the intake air 1 enters.

[0025] Between the entry area of the intake air 1 through the inlet openings 20 in the hood 13 and the cyclone air filters 10, according to the invention the pre-separation device 2 is located, which is for example configured as a labyrinth filter 12, and the pre-separation device 2 can also be configured in alternative embodiments, for example as a pre-cyclone air filter with a corresponding opening width.

[0026] The pre-separation device 2 is formed by multiple wall elements 15 and 16, wherein first wall elements 15 are configured at the carrier 14, and further wall elements 16 are configured at the hood 13.

[0027] Further, the pre-separation device 2 comprises a dirt collection area 18, which is arranged below the wall elements 15 and 16 with reference to an unusual operative position of the angle grinder. The dirt collection area 18 is formed in a space between the carrier 14 and the hood 13, and the hood 13 has openings 19 in the region of the dirt collection area 18. Through the openings 19 contaminations can be lead out of the dirt collection area 18, for example if an operator lets pressurized air or a jet of water enter through the air inlet opening 20.

[0028] The wall elements 16 at the hood 13 are configured in such a way that a front wall element 16 forms a moisture protection 17. The moisture protection 17 prevents the ingress of water entering through the air inlet openings 20 into the rear area of the air intake zone, wherein further protection elements are formed by barriers 21, which cover the entry area of the cyclone air filter 10 in a half-shell shape. Therefore, the intake air 1 has to flow around the outsides of the barriers 21, which prevents moisture, in particular water droplets, but also contaminations from being carried along into the cyclone air filter 10.

[0029] FIG. 3 shows a bottom view of the hood 13 with the wall elements 16 configured at the inner sides of the hood 13. Further shown are the openings 20 for removing the contaminations and the air inlet openings 20 for the entry of the intake air. The view shows the wall elements 16 with a front wall element, which forms the moisture protection 17.

[0030] FIG. 4 shows a view of the carrier 14 with a filter body 11 which can be inserted on the top side and with the cyclone air filters 10. Between the cyclone air filters 10 with the barriers 19, the wall elements 15 extend approximately in horizontal direction. Below the wall elements 15, the dirt collection area 18 is located, which is covered on the front side by the hood 13 (not shown).

[0031] If the hood 13 according to FIG. 3 is attached to the carrier 14 according to FIG. 4, the space between the cyclone air filters 10 is substantially closed, and the wall elements 15 and 16 getting into interaction cause the entering intake air to be diverted in a labyrinth-like manner, so that contaminations accumulate in the dirt collection area 18.

[0032] The invention is not limited to the preferred exemplary embodiment stated above. On the contrary, a number of variations are possible, which make use of the shown solution even with embodiments of a fundamentally different type. All features and/or advantages deriving from the claims, including design details, spatial arrangements and method steps, can be substantial to the invention both by themselves as well as in any combinations.

LIST OF REFERENCE SIGNS

[0033] 100 angle grinder [0034] 1 intake air [0035] 2 pre-separation device [0036] 10 cyclone air filter [0037] 11 filter body [0038] 12 labyrinth filter [0039] 13 hood [0040] 14 carrier [0041] 15 wall element [0042] 16 wall element at the hood [0043] 17 moisture protection [0044] 18 dirt collection area [0045] 19 opening [0046] 20 air inlet opening [0047] 21 barrier