EP3517011A1 - Filter assembly for reducing noise for a vacuum cleaner - Google Patents

Abstract

The invention relates to a filter arrangement (10) for reducing noise for a vacuum cleaner with a first filter area (1) of a filter, which differs from at least one predetermined property from at least one further filter area (2, 3, 4, 5), the first The filter area (1) and the at least one further filter area (2, 3, 4, 5) partially overlap one another and / or at least partially enclose one another so that the filter areas (1, 2, 3, 4, 5) are regular Inflow surface (6) and a regular outflow surface (7) which is plane-parallel to the inflow surface (6) for air flowing through the filter arrangement, the first filter region (1) and the at least one further filter region (2, 3, 4, 5) on the The inflow surface (6) and / or adjacent air-permeable partial surfaces on the outflow surface (7) define the different egg predetermined from each other have properties. Through a targeted combination of properties and / or an arrangement of filter areas (1, 2, 3, 4, 5), the filter arrangement (10) can be optimally adapted to the needs of the user or to a sound to be damped and / or a necessary cleaning and The invention relates to a vacuum cleaner provided with such a filter arrangement (10).

Description

FIELD OF THE INVENTION

The present invention relates to a sound-reducing filter assembly for a vacuum cleaner according to the preamble of claim 1 and a vacuum cleaner provided therewith according to claim 13.

STATE OF THE ART

From a physical point of view, sound is nothing more than the generation and transmission of vibrations. These vibrations can be generated and transmitted by different objects and / or by an air flow. Furthermore, vibrations of surfaces can be reflected. This phenomenon is called echo, whereby an amplitude of the oscillation and thus a human perceivable loudness of the oscillation can be reflected or amplified. Depending on the frequency and amplitude, the sound of humans can be perceived as a loud unpleasant and disturbing noise.

For some time now, developers have been trying to minimize noise emitted by vacuum cleaners to increase usability and application. Especially with the use of vacuum cleaners in an environment in which many people are affected by the disturbing noise, for example in an apartment building, an office building or depending on the time of day, a reduction of the outgoing disturbing noise is absolutely necessary.

In a conventional construction of vacuum cleaners, an airflow generated by an engine-blower unit is generated which picks up dust and dirt and passes it into a housing containing the engine-blower unit, in which it is cleaned. In a smaller design, as is customary in hand vacuum cleaners, the dirt-enriched air is cleaned in the housing. Thereafter, the purified air passes through the motor-blower unit to cool it. Only in this way is a construction possible for current transportable devices. When air flows through a vacuum cleaner, airborne sound is produced - similar to the sound that occurs when the window is opened when driving in a car. Developers reduce airborne noise by removing obstacles such as sharp edges and slight bends in the course of the airflow. This avoids turbulence in the air flow, which may be responsible for the formation of airborne sound. In the case of conventional vacuum cleaners, therefore, high-performance nozzles are used and connections are sealed particularly well and surfaces bordering on the air flow are smoothed. In addition, the airways in the discharge area have been improved so that the air flows slower and thus quieter.

From the prior art, for example, the DE 10 2011 007 204 A1 known, in addition to the reduction of dust and odor nuisance during the blowing of exhaust air by means of a motor-blower unit by a downstream thereto arranged filter arrangement noise pollution is taken into account, which is caused by diffuse Luftverwirbelungen or turbulent flow conditions. In this case, an exhaust air stream is passed into an air-permeable and sound-absorbing foam filter on an upstream side of an air-permeable and sound-absorbing foam filter, wherein on at the downstream side of the foam filter, the foam filter at least partially covering air-impervious baffle is arranged so that the exhaust air flow deflected in the foam filter from its main flow direction can be. Thus, a noise reduction takes place only in the blow-out area, wherein a covering air-impermeable baffle covers a part of the filter.

A similar solution is from the document CH 409 267 A known. The invention is essentially characterized in that an exhaust opening in a vacuum cleaner housing is covered by a protective cover, and that under the or a filter is arranged in the protective cover through which the air emerging from the exhaust opening flows. In order to prevent the air from the exhaust opening flows directly through the thin upper filter layer and to obtain a better air distribution, this filter layer is provided above the region of the exhaust opening with a layer of air-impermeable material, preferably polyethylene. This layer can be provided on the underside or the top of the filter layer or can lie with the filter layer in the same plane. However, the layer of air-impermeable material causes a smaller flow area for the exiting air, so that the vacuum cleaner must be operated with higher energy consumption, which in turn leads to an increase of the running noise of the motor-blower unit

Another filter arrangement with sound-absorbing effect is from the document DE 43 15 712 A1 known, in which two in the form of a staircase-shaped pyramid superimposed filter layers are arranged, whereby the filter layers overlap only partially. The staircase shape is determined by a multi-graduated basket-like attachment, in which the individual filter layers are combined to form a sandwich filter. Since the inflow surface of the filter assembly does not correspond to the outflow surface of the air flowing through it, a flow area formed by such a filter assembly can not be fully utilized.

Accordingly, the existing solutions for reducing unpleasant noise or sound are not yet fully developed and still offer a wide field of improvement worthy of improvement.

OF THE INVENTION PURSUANT TASK

The invention is based on the object to provide a compact filter assembly for a vacuum cleaner, which allows improved noise reduction while maintaining or increasing their filter performance. In addition, it is an object of the invention to provide a vacuum cleaner with the filter assembly according to the invention, which works at the same time quiet in maintaining or increasing a cleaning performance and / or a suction power of the vacuum cleaner.

INVENTION SOLUTION

The solution of the problem is achieved with a filter assembly having the features of claim 1 and a vacuum cleaner provided with the features of claim 13.

According to the invention, the filter arrangement for noise reduction for a vacuum cleaner is designed to be flat and comprises a first filter region of a filter and at least one further filter region which differs from the first filter region, wherein the first filter region and the at least one further filter region partially overlap one another and / or at least partially adjacent to each other, wherein the filter areas form a regular inflow area and a plane parallel to the inflow surface regular Ausströmungsfläche for an air flowing through the filter assembly, so that the first filter area and the at least one further filter area on the inflow surface and / or on the Ausströmungsfläche adjacent air-permeable Define faces that differ from each other by at least one predetermined feature. Through a specific combination of properties and / or an arrangement of filter areas or partial areas, the filter arrangement can be optimally adapted to the needs of the user or to a sound to be damped and / or a required cleaning and / or suction power by a specific filter area or a certain area is selected a material with a desired flow resistance and / or a sound-absorbing effect of the air. Due to the flat design of the filter assembly, a filter can be installed to save space. The special nature of the shape of a regular inflow surface or outflow surface offers no corners in their longitudinal extent, so that it provides little or no Verwirbelungsmöglichkeiten an air flow. Furthermore, sound waves are not scattered in any direction.

For the purposes of the invention, the term "property of a filter area" of a filter arrangement or of a filter is understood to mean a peculiarity or peculiarity of the filter or filter material, which with regard to a material Composition and manufacture, a geometry, an electromechanical and chemical property and mode of action is distinctive.

The term "regular area" or "differentiable area" is used to precisely define the commonly used concept of area in the mathematical context. The definition clearly shows that one deforms partial surfaces or pieces of a plane in such a way that no corners or edges arise; or so merges together or composed that you can create a tangent plane at each point of the resulting structure. In the present case, this tangential plane is plane-parallel to the inflow surface and plane-parallel to the outflow surface. In contrast to the topological surface, on the regular surface, due to the existence of a tangent plane, one can explain a derivation of an image; from Wikipedia: Regular Surface Available on: 12.12.2017 available at: https://de.wikipedia.org/wiki/Regular_Fläche.

Furthermore, the term inflow surface or the outflow surface facing away from it means the surface through which the air flows, which corresponds to an area extent of the filter, wherein in the sense of the invention the surface area of the inflow surface is the same as the surface area facing away from the outflow surface. Furthermore, in particular, these filters, which form a regular surface, according to the following embodiments are aligned substantially perpendicular to a flow direction of the air to be filtered. The flow direction of the air always means the direction of the air flow from the higher to the relatively lower pressure. This is understood to mean essentially a direction from the inflow surface to an outflow surface, which faces away from it, of the air flowing through the filter arrangement. For the purposes of the invention, both the inflow area and the outflow area facing away from it are basically as large as the throughflow area of the filter. As a result, essentially the entire flow-through filter surface is used.

A surface or surface area has in the sense of the invention with its length and width two dimensions or dimensions and is defined by an outline in shape. Furthermore, planarity or planarity analogously designates the spatial arrangement - ie three-dimensional space of points in a plane; the points are then plan - in mathematics: komplanar. Two flat surfaces, which are parallel, are plane-parallel according to the invention.

Adjacent to one another is understood in the sense of the invention as meaning that two or more partial surfaces are arranged partially adjacent to one another in the same inflow surface or outflow surface and thus form a composite throughflow surface in the longitudinal extent of the filter surface.

Overlapping is understood in the sense of the invention so that two or more filter areas of the flow area partially cover or overlap or overlap.

Partial enclosing in the sense of the invention means an adjoining and / or delimiting a filter area of at least one side of its surface, wherein complete enclosing means an all-round delimitation or encasing of its surface.

In conventional filter assemblies, flat filter sheets are sandwiched perpendicular to a flow direction. Such a filter arrangement thus has the same filter properties over the entire flow area. In contrast, a filter arrangement according to the invention, however, has individual filter areas or partial areas whose filter properties differ from those of an adjacent filter area. Depending on the desired embodiment, it is possible in this way to assemble a filter which, depending on a filter area or the surface area of its partial area, may have certain but different characteristics. For example, a filter or the filter surface of the filter assembly may be composed of concentric rings which adjoin one another. In a further advantageous embodiment, for example, two rectangular filter areas partially overlap each other.

Another aspect of the invention relates to a vacuum cleaner having at least one noise reduction filter assembly, the vacuum cleaner comprising: a dust collection unit configured to deposit contaminants from an aspirated airflow; an engine-blower device configured to generate the airflow; and at least one opening, which is arranged in front of and / or after the motor-blower device and through which opening the air flow can be passed. In order for the vacuum cleaner with the filter arrangement the highest possible noise attenuation can be achieved, the filter assembly of the motor-blower device of the vacuum cleaner is upstream and / or downstream stored in the flow direction of the air flow. Depending on the location of the occurrence of the sound, e.g. at an inlet and / or outlet opening of the motor-blower unit of the vacuum cleaner, the sound emitted to the outside can be greatly reduced by means of the filter arrangement.

Compared with conventional filters, the filter assembly according to the invention allows a significant reduction in noise when used in a vacuum cleaner provided with it, without having to accept any restrictions on the suction and / or cleaning performance of the vacuum cleaner. Thus, the filter assembly according to the invention is particularly suitable for low-power vacuum cleaner devices in which the suction power is already greatly reduced due to the low performance of the motor-blower device. In addition, the ease of use of the devices equipped with such a filter assembly is improved because noise due to the operation of the motor-blower device of the vacuum cleaner and unpleasant noise caused by the air flowing in the vacuum cleaner, steamed or completely avoided become.

PREFERRED EMBODIMENT OF THE INVENTION

Advantageous embodiments and developments, which can be used individually or in combination with each other, are the subject of the dependent claims. The advantages applicable to the filter assembly apply equally to a vacuum cleaner provided with it and operated.

In an expedient embodiment of the filter arrangement, at least one property of a material of the respective filter region of the filter arrangement has a predetermined flow resistance.

In the process of filtering the interaction of air permeability of the filter assembly and a so-called pressure difference of importance, which is caused by the flow resistance of the filter of importance. Prior to the filter assembly, a relatively higher pressure builds up than behind the filter, where the pressure is lower in relative comparison. A low pressure difference in conjunction with a high air permeability or a low flow resistance of the filter reduces the energy required to convey a certain amount of air through the filter assembly. In a vacuum cleaner, a flow field of the air flowing through and / or a sound distribution field are not homogeneous. This means that the pressure and flow velocity of the air and the distribution of sound are not the same everywhere or are even.

By a targeted selection of the material for a particular filter area as a function of a desired flow resistance of the filter, the energy efficiency of the filter or a vacuum cleaner operated therewith can be increased and at the same time a permanent cost savings in the operation of the vacuum cleaner can be ensured with such a filter arrangement. By adjusting the flow resistance in the choice of material, a minimum volume flow of air to be cleaned and thus a certain cleaning performance of the vacuum cleaner can be ensured.

Alternatively or additionally, in a further advantageous embodiment of the filter arrangement, at least one predetermined property of a material of the respective filter region is selected as a function of a specific sound frequency or sound frequency spectrum to be absorbed.

Through a specific combination and the arrangement of filter materials for a specific filter area of the filter arrangement, the filter arrangement can be optimally adapted to the needs of the user or to the sound to be damped. Certain sound-insulating materials filter contaminated air and damp or simultaneously absorb different sound frequencies. This is particularly important for a sound reduction at frequencies below 2000 kHz.

Alternatively or additionally, in yet another advantageous embodiment of the filter arrangement, at least one predetermined property of the material of the respective filter area is selected as a function of a specific sound frequency or sound frequency spectrum to be reflected.

Through a targeted selection of the material and arrangement of the filter areas, the filter arrangement can act as a diffuser or reflector of sound waves. By means of a steering and frequency-wise dispersion of the sound waves, different sections can be created in a housing of the vacuum cleaner in which the sound emitted by a sound source is maintained quantitatively to a desired proportion. In addition, the effect of the reflection on the walls of the housing of the vacuum cleaner or on the walls surrounding the filter assembly is partially canceled. In addition, the sound waves in this way can be steered and determined in their amplitude and frequency, so that they counteract a structure-borne noise, which is caused by the motor-blower unit, by damping this or cancel.

In a particularly expedient embodiment of the filter arrangement, at least one filter region of the filter is essentially soundproof. Soundproofing is understood to mean that no sound of a certain sound spectrum penetrates from one area to another area. Such a filter arrangement is particularly suitable for a filter which is connected downstream of a motor-blower unit and is arranged in front of an air outlet opening of the vacuum cleaner, as he just before the exit of the sound reflected this again in the direction of the motor-blower unit and the No sound at all or only indirectly. In a further embodiment, an air- and / or sound-impermeable filter area is arranged such that the speed of the air flow is slowed once again just before exiting the vacuum cleaner housing.

In yet another suitable embodiment, the first filter arrangement has a thickness and / or expansion which differs from the at least one further filter arrangement. As a result, the individual filter regions can also be adapted specifically to the flow field or the velocity field of the air impinging on the filter arrangement, with the aim of achieving a homogeneous flow field of the air after passing through the filter.

Expediently, the first filter region differs from the at least one further filter region in terms of its geometric shape. In particular, a proportion of the surface area of the partial area and / or thickness of the first filter area amounts to 5% to 95% of the proportion of the area extent of the partial area and / or the thickness of the at least one further filter area. In further embodiments, a proportion of the surface area and / or thickness of the first filter region is preferably 25% to 75% and particularly preferably 40% to 60% of the proportion of the surface area of the partial area and / or the thickness of the at least one further filter area. The individual filter areas can therefore be adapted specifically to a specific flow field or velocity field of the air impinging on the filter arrangement. This makes it possible to achieve a nearly homogeneous flow field of air after passing through the filter, thereby avoiding turbulence, which are responsible for the generation of unpleasant noise. The filter areas may be circular, elliptical, rectangular, trapezoidal or annular. Depending on the application, the filter assembly may also be part of a filter device which has the shape of a cuboid, truncated cone or a cylinder - as occurs for example in vacuum cleaners with centrifugal separators.

Preferably, the filter assembly has a thickness of 2 millimeters to 50 millimeters. Depending on the flow field of the air, the degree of contamination of the air and / or spatial conditions for the use of the filter assembly, the thickness of the filter assembly can be optimally adapted to the needs of the user. For example, thin filters are made of so-called felt materials, thicker filters usually made of foams. For the purposes of the invention, in a filter arrangement, the filter materials can be formed from a single type of material as well as from different materials.

In yet another preferred embodiment, the first filter region has a different density than the at least one further filter region. For example, a higher density of a filter area simultaneously causes an increase in flow resistance through the higher density filter area. In addition, the density of the filter area also depends on a desired degree of purification of the air. In conjunction with a specific selection of the thickness and density of the filter area, the flow field of the air impinging on the filter arrangement can be influenced even more differentiated and better, so that turbulences can be minimized after passing through the filter arrangement, which in addition has a sound-reducing and energy-saving effect.

In other words, a targeted selection of the thickness and / or density of the filter material in the individual filter areas of the filter arrangement makes it possible to influence a flow resistance in the filter areas of the filter arrangement through which the air flows. In order to achieve a homogeneous flow field after passing through the filter arrangement, a distribution / arrangement of the flow resistance of individual filter areas of the filter arrangement according to an advantageous embodiment, so that the flow resistance is directly proportional to a distribution of the flow velocity in the flow field of the air flow, which is the flow area of the filter assembly equivalent. Thus, for example, the first filter region may have a lower air permeability or a higher flow resistance compared with the at least one further filter region and / or the first filter region may have a higher acoustic impedance or a higher sound absorption or sound reflection degree than the at least one further filter region.

An expedient embodiment of the filter arrangement has at least two different materials perpendicular to the direction of the air stream flowing through it in an overlap region of the first and the at least one further filter region. The overlap region can be arranged and selected depending on a desired flow resistance. Advantageously, the overlap region is arranged perpendicular to the direction of the air flow flowing through it. In addition, an overlap of the two filter areas is advantageous because it avoids gaps in a connection of the two filter areas, which would greatly affect the function of the filter assembly. In addition, the filter arrangement can also be mechanically stressed for a short time, since the individual filter areas in the overlapping area can move relative to one another without the filter function being impaired as a result.

In an advantageous embodiment, the filter arrangement has an air-permeable wall in a transition region of the first filter region and the at least one second filter region. As a result, a precise separation of the filter areas of the filter arrangement is possible. Furthermore, the air-permeable wall acts as a reinforcement and / or stiffening of the filter assembly. At the same time, the wall itself forms an air-permeable filter area, acting like another filter area.

In a further advantageous embodiment, the air-permeable wall forms a frame around the material of a filter area. As a result, a separate replacement of the filter material of certain filter areas is possible if the air-permeable wall forms a frame enclosing the filter material of the filter area and / or is designed as a holder of the filter material. By flexibly exchanging a desired filter material, the use can be easily changed and adapted.

Practically, the filter arrangement according to one embodiment comprises at least one sound-damping material from the group polyurethane, polyethylene, polystyrene, polypropylene and melamine, preferably foams of the material. These materials are inexpensive to manufacture and process and have a long life and usability due to their durability. Depending on the application, the materials of the filter are produced as nonwovens, woven and knitted or by foaming.

The vacuum cleaner expediently has a filter arrangement with at least one partial surface, which is defined by a first filter region and at least one further adjacent filter region, which differs from the first filter region, on an inflow surface and / or on an outflow surface of the filter arrangement, wherein the partial surface is at least partially covers the opening at a predetermined distance from the opening. An only partial overlap of the area of the flow cross section of the air through the opening can then be selected if structural or acoustic conditions make this necessary. For example, the filter assembly can also be arranged obliquely or offset relative to a position of the opening. A large overlap of the opening allows a particularly good sound insulation depending on a selected filter material. At the same time, due to the larger flow area of the filter arrangement, a denser filter material or a lower power motor-blower unit can be selected than for small flow areas.

Depending on the above-mentioned exemplary restrictions or framework conditions, a size of the partial area of the filter arrangement in the vacuum cleaner is 50% or preferably 100% or particularly preferably 200% of a size of the opening. In further embodiments, a size of the partial area can in principle also be greater than 200% or less than 50% of the size of the opening. The choice of the size of the partial area can also be selected as a function of the predetermined distance of the filter arrangement from the opening.

In order to minimize possible natural frequencies or resonance frequencies of the motor-blower unit, the filter assembly or the vacuum cleaner associated therewith, the filter assembly is mounted according to an advantageous embodiment in the vacuum cleaner at least partially elastic. As a result, a structure-borne noise emanating from the vacuum cleaner is also effectively reduced to reduce the airborne sound.

By the present embodiments of the invention providing a combination of multiple filter areas of a filter having different properties, efficient sound reduction can be achieved while maintaining or increasing the suction power of a vacuum cleaner equipped therewith. In addition, the usability and customer satisfaction are significantly increased.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1

veranschaulicht in einer perspektivischen Ansicht das Innenleben eines Staubsaugers mit einer darin anbringbaren Filteranordnung gemäß einer vorteilhaften Ausführungsform;

Fig. 2

veranschaulicht eine Draufsicht auf eine Filteranordnung mit mehreren Filterbereichen gemäß einer vorteilhaften Ausführungsform;

Fig. 3

veranschaulicht mehrere Ausführungsbeispiele 3a - 3e einer vorteilhaften Ausführungsform der Filteranordnung und seiner Filterbereiche in einer Schnittansicht entlang der Schnittlinie A - A.

Further advantageous embodiments will be described in more detail below with reference to an embodiment shown in the drawing and various embodiments thereof, to which the invention is not limited.

Fig. 1

Figure 3 illustrates in a perspective view the interior of a vacuum cleaner with a filter assembly attachable therein according to an advantageous embodiment;

Fig. 2

illustrates a top view of a filter assembly having multiple filter areas according to an advantageous embodiment;

Fig. 3

illustrates several embodiments 3a - 3e of an advantageous embodiment of the filter assembly and its filter areas in a sectional view along the section line A - A.

DETAILED DESCRIPTION OF THE DRAWING

The reference numbers in all claims have no limiting effect, but are only intended to improve their readability. Identical reference symbols in different figures indicate similar or equivalent elements.

Based on Fig. 1 In the drawing, an advantageous embodiment of a vacuum cleaner 100 is shown with an attachable therein filter assembly 10 according to an advantageous embodiment.

In the present embodiment, the filter assembly 10 is disposed in front of an opening 13, which leads from a Staubabscheideeinheit 11 in an engine-blower unit 12 of the vacuum cleaner 100. For this purpose, the filter assembly 10 is mounted in a holder 14 of the vacuum cleaner 100 in front of the opening 13. Depending on the embodiment, the holder 14 may be designed to support the filter assembly 10 elastic so that it dampens sound waves that may be caused by vibrations of the filter assembly 10, the motor-blower unit 12 or the vacuum cleaner 100.

The filter assembly 10 shown in the embodiment of the vacuum cleaner 100 has a rectangular shape. In a further, not shown embodiment of the filter assembly 10, the filter assembly can take a circular, elliptical or any polygonal shape. Due to the flat design and the material used of the filter assembly 10, these can be arbitrarily cut according to a particular embodiment, so that it can be used flexibly in various vacuum cleaners 100 or at specific openings 13 for passing an air flow. In the Fig. 1 a conventional vacuum cleaner 100 is shown for filter bag, the invention is not limited thereto, but also includes bagless vacuum cleaners, or vacuum cleaners having a centrifugal separator.

Furthermore, the filter arrangement 10 can additionally or alternatively be arranged at further openings 13 through which air can flow or is conducted, for example at an outlet region of the vacuum cleaner 100, which is connected downstream of the motor-blower unit 12 in the direction of the air flow and through which the air, or the sound can penetrate to the outside.

Preferably, the filter assembly 10 is arranged according to an advantageous embodiment perpendicular to a flow direction of the air. Depending on a sound and / or the flow direction of the air, the filter assembly 10 according to another preferred embodiment - not shown here - are arranged at a predetermined angle to the direction of the air flowing to the filter assembly 10 air. As a result, the sound can be directed in a certain direction and / or an air resistance can be influenced by the filter arrangement 10. By means of the orientation of the filter arrangement 10 for the air flow, it is possible to influence specifically the properties of a flow field or a velocity field of the air impinging on the filter or the filter arrangement 10. Apart from an orientation of the filter assembly 10 to the air flow or a targeted storage of the filter assembly 10 at a predetermined distance, for example, before and / or after a motor-blower unit 12 can be a sound emission of the equipped with the filter assembly 10 vacuum cleaner 100 based on other properties of Influence filter arrangement 10.

In the Fig. 2 a filter assembly 10 according to the invention with a plurality of filter regions 1, 2, 3, 4, 5 of the filter assembly is shown in a plan view of an inflow surface 6 of the filter assembly 10. In the sense of the embodiment, both the inflow surface 6 and the outflow surface 7 facing away from it are basically as large as a throughflow surface of the filter. As a result, essentially the entire flow-through filter surface is used. The inflow surface 6 of the filter assembly 10 has a substantially rectangular shape. It comprises a first filter region 1 of a filter 1, which differs by at least one predetermined property from a further filter region 2, 3, 4, 5, here a second filter region 2. The first filter region 1 and the at least one further filter region 2, 3, 4, 5 define adjacent partial surfaces on the inflow surface 6 and / or on the outflow surface 7 which, for example, have different properties with regard to sound insulation and / or flow resistance. The filter areas 1 and 2 may differ in the nature of their material composition, in terms of their physical and chemical properties, their shape and production. The properties of the individual filter areas 1, 2, 3, 4 and 5 are preferably selected such that they are matched to a vacuum cleaner 100 or a specific flow and sound field of the air, so that a possible energy-efficient and effective cleaning of the polluted air allows and additionally or alternatively, a sound emanating from the vacuum cleaner 100 or from the air flowing through the filter arrangement 10 is attenuated. For this reason, for example, a first filter region 1 of the filter arrangement 10 is preferably arranged directly before or after the opening 13 of the motor-blower unit 12 of the vacuum cleaner 100. In this case, the first filter region 1 of the filter arrangement 10 is more air-tight and stiffer than the second filter region 2 of the filter arrangement 10 Fig. 2 the filter area 1 of the filter arrangement 10 is encompassed by the second filter area 2. As a result, it is possible with the filter arrangement 10, for example, to specifically reflect and / or absorb the sound waves entrained in the air flow. By a specific selection of the material of the filter areas 1, 2 of the filter arrangement 10, individual frequencies or specific frequency ranges can be attenuated or completely filtered out. Particularly expedient embodiments of the filter arrangement 10 have sound-damping materials from the group polyurethane, polyethylene, polystyrene, Polypropylene and melamine on. The materials are preferably foams used as foams.

In the present embodiment of the Fig. 2 the filter area 1 is delimited in a transition region to the filter area 2 via a wall 8. The wall 8 acts here as an independent frame for the filter area 1 and as a wall 8 at the same time even an air-permeable filter area. This is particularly advantageous if only one filter area 1 or 2 of the filter assembly 10 is to be selectively replaced. Reason for this may be, for example, uneven wear of the two filter areas 1, 2 of the filter assembly 10. Apart from that, the filter assembly 10 can be flexibly adapted to changed noise emissions and sound waves of the vacuum cleaner 100 and the motor-blower unit 12, respectively.

Depending on an available installation space in the vacuum cleaner 100 as well as a recordable power or a desired sound insulation of the vacuum cleaner 100, a partial area of the inflow area 6 and / or on the outflow area 7 can be specifically adapted since the partial area has a predetermined selected property. This size can also be selected in particular as a function of the overall size of the filter arrangement 10. Particularly preferably, a size of the partial area of the filter arrangement 10 in the vacuum cleaner 100 is selected to be between 50% and 200% of a size of the opening 13. In further embodiments, a size of the partial area can in principle also be greater than 200% or even less than 50% of the size of the opening 13. The choice of the size of the partial area can also be selected as a function of the predetermined distance of the filter arrangement from the opening 13. For example, the greater the distance of the filter assembly 10 from the aperture 13, the greater the size of the patch should be selected relative to the size of the aperture 13 surface. In the present example according to Fig. 1 corresponds to the area of the opening 13 - not shown - in approximately the circular partial area, which is given by the first filter area 1. A low power of the vacuum cleaner 100 or small space in the vacuum cleaner 100 requires that the distance between the opening 13 and the filter assembly 10 is smaller. At the same time, a smaller distance also leads to higher flow-related noise, which by means of a targeted choice of the size of the Partial surface can be prevented or minimized. Expediently, spacings between 5 mm and 20 mm are generally selected.

In Fig. 3 For further illustration, several exemplary embodiments 3a, 3b, 3c, 3d and 3e of an advantageous embodiment of the filter arrangement 10 and its filter areas 1, 2, 3, 4 and 5 are shown in a sectional view along a notional section line AA Fig. 2 shown. The filter assembly 10 from Fig. 3 shows further embodiments of one with the filter assembly 10 of the Fig. 2 In the exemplary embodiments 3a, 3b, 3c, 3d, a first filter region 1 is not completely encompassed or enclosed by the further filter region 2, 3, as in the embodiment of FIGS Fig. 2 is shown.

The individual filter areas 1, 2, 3, 4 and 5 may correspond to different materials in the present embodiments 3a, 3b, 3c, 3d and 3e.

In conventional filter assemblies 10, flat filter filter regions 1, 2, 3, 4, and 5 completely sandwiching one another are arranged perpendicular to a flow direction. Such a filter, or such a filter arrangement 10, has the same properties over the entire throughflow area 6 with regard to a sound insulation and / or a flow resistance of the air flowing through the filter arrangement.

Embodiments 3a to 3e of the embodiment in FIG Fig. 3 is common that they have a regular flow area 6. In other words, the individual filter areas 1, 2, 3, 4 and 5 do not form staircase-shaped surfaces. In addition, the filter regions 1, 2, 3, 4, 5 of the throughflow surface of the filter assembly 10 are formed so that they partially overlap each other partially adjacent to each other and / or at least partially adjacent to each other. By a specific combination of the properties and / or the arrangement of the filter areas 1, 2, 3, 4, 5, the filter or the filter arrangement 10 can be optimally adapted to the needs of the user with regard to a sound to be damped and / or a required cleaning and / or Suction power can be adjusted by at least one specific filter area 1, 2, 3, 4, 5 of the filter assembly, a material with a desired flow resistance and / or a required sound-insulating effect of the air is selected.

In this case, the first embodiment 3a shows a particularly simple implementation of the filter arrangement 10 by means of only two filter areas 1, 2. The two filter areas 1, 2 have, for example, different materials whose density and / or flow resistance and / or elasticity differ from each other. The denser a material, the higher its flow resistance, and the higher its reflectance of sound waves. The more elastic a material is, the more sound it can absorb. The advantages which apply to embodiment 3a also apply to the further embodiments 3b, 3c, 3d and 3e.

Another embodiment 3b shows a variant of the embodiment 3a in which the first filter region 1 can be almost completely surrounded by the second filter region 2. The special arrangement can be understood in analogy to the theory of electricity in the area of the partial overlapping of the filter areas 1, 2 as a series connection or addition of certain properties. The flow properties and sound properties of the air can be influenced in a more targeted manner on the basis of a predetermined geometric shape and thickness of the second filter region 2. The thicker a certain filter area - in this case filter area 2 - compared to a further filter area 2 of the same material, the higher, for example, its sound-absorbing effect and / or the higher is the opposite of an air flow passing through the filter assembly air flow resistance. It may also be that due to structural and spatial restrictions at the location where the filter assembly 10 is to be installed, the embodiment 3b can be used particularly advantageously, wherein the combination of the first filter area 1 with the second filter area 2, the lack of thickness in a partial area of the second filter region 2 can compensate. In order to save space, the individual embodiments 3a to 3e essentially have a constant thickness. By thickness is meant the distance from the inflow surface 6 to the outflow surface 7, which the air passing through the filter arrangement travels. For the purposes of the invention, the inflow surface 6 and the outflow surface 7 remote therefrom are basically as large as the throughflow area of the air. To allow a flexible adaptation to different flow velocities of the air is a proportion of Surface area of the partial area and / or thickness of the first filter area 1 between 5% to 95%, preferably between 25% to 75% and particularly preferably between 40% to 60% of the proportion of the surface area of the partial area and / or thickness of the at least one further filter area 2 , 3, 4, 5 selectable.

The embodiment 3c shows a further possibility of combining three filter areas 1, 2 and 3 in a further advantageous arrangement. In this case, the first filter region 1 is embedded in the second filter region 2. Looking back Fig. 2 This exemplary embodiment can be considered as a variant of the exemplary embodiment extended by a filter region 3 Fig. 2 be seen.

In yet another advantageous exemplary embodiment 3d, further filter regions 1, 3, 4, 5 are received or integrated in the second filter region 2. The individual further filter areas 1, 3, 4, 5 can be understood as concentric circles or parallel adjacent rectangles, etc. Such an arrangement of the filter areas 1, 3, 4, 5 may be advantageous at certain frequencies and / or sound patterns in interaction with different flow resistances of the material of the filter areas 1, 3, 4, 5.

In yet another exemplary embodiment 3f, further filter regions 1, 3 and 2 are embedded in a second filter region 2 in the manner of a bowl in the filter region 2 like an onion.

For simplifying purposes of illustration, the thickness of embodiments 3a to 3e of the filter assembly 10 has been chosen to be qualitatively constant. It should be noted at this point that, for example, the thickness of a blow-out filter of a vacuum cleaner 100 can have up to 50 millimeters, while other filter combinations only have a thickness of 2 millimeters. Furthermore, the individual filter regions 1, 2, 3, 4, 5 can also be arranged obliquely within an adjacent filter region 1, 2, 3, 4, 5 to one another.
In summary, the advantages of the respective embodiments are in part transferable to one another and can be linked to one another. By a specific combination of properties and / or arrangement of filter areas 1, 2, 3, 4, 5, the filter assembly 10 optimally to the needs of the user or be adapted to the sound to be damped and / or a required cleaning and / or suction power by, for example, in the filter areas 1, 2, 3, 4, 5 a material with a desired flow resistance of the air is selected.

The features disclosed in the foregoing description, the claims and the drawings may be of importance both individually and in any combination for the realization of the invention in its various forms.

LIST OF REFERENCE NUMBERS

1

first filter region of the filter assembly

2

further filter area, second filter area of the filter arrangement

3

further filter area, third filter area of the filter arrangement

4

further filter area, fourth filter area of the filter arrangement

5

further filter area, fifth filter area of the filter arrangement

6

inflow

7

outflow area

8th

wall

10

A filter assembly

11

Staubabscheideeinheit

12

Motor-fan unit

13

opening

14

Storage or mounting of the filter assembly

100

vacuum cleaner

A-A

intersection

Claims (15)

A noise reduction filter assembly (10) for a vacuum cleaner (100) comprising: a first filter region (1) and at least one further filter region (2, 3, 4, 5) different from the first filter region (1), the first filter region (1) and the at least one further filter region (2, 3, 4, 5) partially overlapping each other and / or at least partially adjacent to each other, so that the filter regions (1, 2, 3, 4, 5) has a regular inflow surface (6) and form an outflow surface (7) plane-parallel to the inflow surface (6) for an air flowing through the filter arrangement, characterized in that the first filter region (1) and the at least one further filter region (2, 3, 4, 5) the inflow surface (6) and / or define on the outflow surface (7) adjacent air-permeable partial surfaces which differ from each other by at least one predetermined property. Filter assembly (10) according to claim 1, characterized in that at least one property of a material of the respective filter region (1, 2, 3, 4, 5) of the filter assembly (10) has a predetermined flow resistance. Filter arrangement (10) according to claim 1 or 2, characterized in that at least one predetermined property of a material of the respective filter region (1, 2, 3, 4, 5) is selected depending on a particular sound frequency to be absorbed or a sound frequency spectrum. Filter arrangement (10) according to any one of the preceding claims, characterized in that at least one predetermined property of a material of the respective filter region (1, 2, 3, 4, 5) is selected depending on a particular sound frequency to be reflected or a sound frequency spectrum. Filter arrangement (10) according to one of the preceding claims, characterized in that the first filter region (1) has a relation to the at least a further filter region (2, 3, 4, 5) has different thickness and / or surface area. Filter arrangement (10) according to claim 5, characterized in that a proportion of the surface area of the partial area and / or the thickness of the first filter area (1) 5% to 95% of the proportion of the surface area of the partial area and / or the thickness of the at least one further filter area (2, 3, 4, 5). Filter assembly (10) according to claim 5, characterized in that the filter assembly (10) has a thickness between 2 millimeters to 50 millimeters. Filter arrangement (10) according to one of the preceding claims, characterized in that the first filter region (1) has a relation to the at least one further filter region (2, 3, 4, 5) different density. Filter arrangement (10) according to one of the preceding claims, characterized in that the filter arrangement (10) in an overlap region of the first filter region (1) and the at least one further filter region (2, 3, 4, 5) has at least two different materials. Filter arrangement (10) according to one of the preceding claims, characterized in that the filter arrangement (10) in a transition region of the first filter region (1) and the at least one second filter region (2) has an air-permeable wall (8). Filter arrangement (10) according to claim 10, characterized in that the air-permeable wall (8) forms a frame around the material of a filter region (1, 2, 3, 4, 5). Filter assembly (10) according to any one of the preceding claims, characterized in that at least one filter region (1, 2, 3, 4, 5) comprises at least one sound-damping material selected from the group polyurethane, polyethylene, polystyrene, polypropylene and melamine, preferably their foams , A vacuum cleaner (100) comprising at least one noise reduction filter assembly (10) according to any preceding claim 1 to 12, wherein the vacuum cleaner (100) comprises: a dust separation unit (11) adapted to separate contaminants from an aspirated airflow; an engine blower device (12) configured to generate the airflow; and at least one opening (13) which is arranged before and after the motor-blower device (12) and through which opening (13) the air flow can be passed, characterized in that the filter arrangement (10) of the at least one opening (13) 13) of the motor-blower device (12) in a flow direction of the air flow upstream and / or downstream. Vacuum cleaner (100) according to claim 13, characterized in that the filter arrangement (10) has at least one partial surface which differs from a first filter region (1) and at least one further adjacent filter region (2, 3, 4, 5) extending from the first Filter region (1), on an inflow surface (6) and / or on an outflow surface (7) of the filter assembly (10) is defined, wherein the partial surface at least partially covers the opening (13) at a predetermined distance from the opening (13) , Vacuum cleaner (100) according to claim 14, characterized in that a size of the partial surface of the filter assembly (10) is 50% or preferably 100% or more preferably 200% of a size of the opening (13).

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