Vacuum hose for a vacuum cleaner, and method for producing same
Patent Information
- Application Number
- EP2023733309
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-30
- Filing Date
- 2023-06-16
- Publication Date
- 2025-05-07
Smart Images
Figure 1.1
Abstract
Description
[0001] Suction hose for a vacuum cleaner and manufacturing method therefor
[0002] The present invention relates to a suction hose for a vacuum cleaner, wherein the suction hose, due to its manufacturing process, has an inner profile with regularly spaced protrusions and flat sections. The inner profile of the suction hose has an embossed flow geometry for flow over the protrusions. This flow effect can significantly reduce eddies and turbulence in the suction hose and make the flow behavior within the suction hose more laminar and with lower losses. In a second aspect, the invention relates to a method for producing such a suction hose.
[0003] Background of the invention:
[0004] In the field of vacuum cleaners, suction hoses are known which often have a spiral or wavy shape. Due to their design, these suction hoses have protrusions that repeat at regular intervals. These protrusions can make it difficult to achieve the desired laminar, i.e. layered, formation of the air flow in the suction hose. In fact, the protrusions lead to eddies that introduce turbulence into the air flow and can disadvantageously lead to flow and energy losses. This turbulence and losses can have a negative effect on the system and / or flow efficiency of the suction hose. The protrusions in the suction hose can also be referred to as grooves, and the grooves can lead to the aforementioned losses in the suction hose. In particular, this leads to friction losses in the area of a main air flow within the suction hose, which are attributable to flow resistance.In the secondary flow within the suction hose, however, losses mainly occur via energy input in transverse vortices.
[0005] Suction hoses in particular comprise a spiral groove, wherein the spiral pitch is generally constant. The area between the grooves is continuously flat and is referred to as a “flat section” in the context of the present invention. In a horizontal section through the suction hose through its axis, a structure repeating at regular intervals can be seen on the cutting plane. Each protrusion and a flat section preferably form a structural unit, wherein the suction hose comprises structural units arranged in a row. When a main or primary flow of the air stream within the suction hose flows over these protrusions, which preferably represent a local change in the cross-section of the suction hose, vortex formation can occur in the area of these protrusions, which in the sense of the invention is preferably also referred to as secondary flow.The resulting vortices can adversely disrupt the airflow boundary layers within the suction hose. The sum of these individual vortices, as well as the turbulence further fueled by the vortices, can lead to very high flow and energy losses, for example, if the ideal geometry of a smooth pipe with the same dimensions is considered as a reference. These losses have a correspondingly significant impact on the system and / or flow efficiency of the suction hose.
[0006] The change in the cross-sectional flow geometry through the grooves perpendicular to the main flow typically results in a secondary flow that is preferably directed essentially perpendicular to the main flow within the air flow in the suction hose. The velocities of the associated vortices are low compared to those of the main flow, but if they are numerous, as in the suction hose, i.e. repeat frequently, they can remove a significant amount of energy from the flow system. The vortices, which are preferably created by the cross-sectional changes associated with the grooves or protrusions, can form a spiral secondary flow in the protrusions or grooves that is oriented perpendicular to the main air flow in the suction hose.
[0007] To prevent such eddies or turbulence, the prior art has proposed at least partially filling the protrusions. For example, DE 10 2011 084 195 B4 proposes using a compressible foam to fill the troughs of the hose profile. However, a disadvantage of filling the troughs can be that the inherently advantageous mechanical properties of the spiral or wave-shaped suction hoses, such as robustness and stability, deteriorate. Furthermore, the at least partially filled troughs or protrusions can become even more easily clogged with dust, which often complicates maintenance of the suction hose.
[0008] Furthermore, the prior art has proposed providing flow bodies on the inside of the suction hose to improve the flow behavior of the air-dust mixture within the suction hose. However, installing such flow bodies on the inside of a suction hose is complex and expensive, and the flow bodies protruding into the inside of the suction hose reduce the flow cross-section. This makes a suction hose designed in this way particularly susceptible to clogging.
[0009] The object underlying the present invention is to overcome the above-described deficiencies and disadvantages of the prior art and to provide a suction hose that exhibits high flexibility while simultaneously being highly wear-resistant and stable, and is also easy to clean and maintain. Furthermore, the suction hose to be provided should have favorable internal flow properties so that the suction flow can flow through the suction hose with as little loss as possible in order to achieve high system and flow efficiency. A further aim of the invention is to provide a manufacturing method for such a suction hose.
[0010] The problem is solved by the subject matter of the independent claims. Advantageous embodiments of the subject matter of the independent claims can be found in the dependent claims.
[0011] Description of the invention:
[0012] According to the invention, a suction hose for a vacuum cleaner is provided. Due to its manufacturing characteristics, the suction hose has an inner profile with protrusions and flat sections that repeat at regular intervals, wherein the inner profile has an embossed flow geometry for flow over the protrusions. The protrusions and the flat sections of the suction hose are particularly clearly illustrated in the figures. Within the meaning of the invention, it is preferred that the suction hose be spiral or wave-shaped and is thus particularly flexible, but also wear-resistant and stable. The spiral or wave-shaped design of the proposed suction hose is achieved by the fact that the suction hose has protrusions and flat sections that repeat at regular intervals.A protuberance and a flat section can each form a structural unit of the suction hose, with these structural units repeating at regular intervals and thus forming the wave or spiral shape of the suction hose. According to the invention, the suction hose is preferably designed as a coiled suction hose with a substantially constant pitch of the protuberances. This basic structure of the suction hose is preferably referred to as the "wave or spiral shape of the suction hose". During operation of the vacuum cleaner, an air-dust mixture is sucked in through the suction hose by a negative pressure in the interior of the vacuum cleaner. This creates an air flow that is preferably oriented primarily from a front region of the suction hose towards the main body of the vacuum cleaner. According to the invention, this air flow is preferably referred to as the main flow or primary flow.In the front area of the suction hose, the suction hose can be connected to a suction or floor nozzle to suck in dust. It may also be preferred within the meaning of the invention for the front area of the suction hose to be connected to a machine tool in order to suck in the dust generated during operation of the machine tool and store it inside the vacuum cleaner.
[0013] The protrusions or grooves represent cross-sectional changes in the suction hose. As a side effect of these cross-sectional changes, which preferably run essentially perpendicular to the main flow, the undesirable, energy-consuming, spiral-shaped secondary flows arise in the protrusions.
[0014] The air flow of the dust-air mixture can flow over the flat sections of the inner profile in a comparatively essentially laminar and uniform manner. In the area of the protrusions, the space available for the air flow widens, and turbulence in the air flow, particularly in the secondary flow, can occur. To reduce the formation and negative flow effects of the protrusions and the associated turbulence, it is proposed in the context of the present invention that the inner profile of the suction hose have a flow geometry. It has been shown that the proposed flow geometry with regularly alternating protrusions and flat sections advantageously leads to the aerodynamic flow over the protrusions.The phrase "aerodynamically flowed over" preferably means, in the context of the invention, that the air can flow over the protuberances with minimal energy losses. This results in significantly less eddies and turbulence within the air flow in the suction hose, and the system and flow efficiency of the proposed suction hose is significantly increased, as flow and pressure losses can be significantly reduced. Tests have shown that, with the flow geometry provided, less dust settles in the protuberances, so that the protuberances only become clogged to a minimal extent even after extended operation. In this way, the suction hose retains its advantageous mechanical properties, such as flexibility and stability. Furthermore, the proposed suction hose has proven to be particularly wear-resistant and low-maintenance.The flow geometry of the inner profile is preferably an embossed flow geometry, which is introduced into the base material of the suction hose by embossing. The base material of the suction hose can preferably be a plastic. By embossing the flow geometry into the base material of the suction hose, a particularly inexpensive suction hose can be obtained or a particularly cost-effective method for producing a suction hose can be provided, since the complex provision of flow bodies on the inside of the suction hose can be dispensed with.
[0015] According to the invention, it is preferred that the flow geometry or its structural elements are arranged in the region of the flat sections of the inner profile of the suction hose. The flow geometry can comprise at least one structural element per flat section, so that the flow geometry can consist of either one or more structural elements. The structural elements of the flow geometry are preferably arranged in the region of the flat sections of the inner profile of the suction hose. Tests have shown that this allows for particularly good airflow over the protrusions of the inner profile. In particular, the air flow does not penetrate deeply into the protrusions, so that turbulence is particularly effectively avoided. In particular, the protrusions can be particularly well airflow over with regard to minimizing secondary flow.
[0016] Within the meaning of the invention, it may be preferred that the flow geometry runs essentially longitudinally to an imaginary central axis of the suction hose. For example, the flow geometry can have at least one longitudinal groove per flat section. The at least one longitudinal groove can run, for example, on a flat section. In this case, the at least one longitudinal groove can run essentially perpendicular to the adjacent protuberances of the inner profile of the suction hose. Preferably, the longitudinal groove has a significantly smaller depth than a protuberance. Within the meaning of the invention, this preferably means that the protuberances are significantly deeper than the longitudinal grooves. The longitudinal grooves preferably run essentially parallel to a central axis of the suction hose. The air flow can penetrate into the longitudinal grooves and interrupts the secondary flow at the interfaces with the grooves.Due to these constant interruptions of the spiral vortices within the suction hose, the intensity of the secondary flow decreases significantly.
[0017] This significantly reduces the turbulence that occurs in conventional suction hoses without flow elements. According to the invention, the longitudinal grooves represent flow or structural elements that run essentially longitudinally or along an imaginary central axis of the suction hose. According to the invention, flow elements that run essentially longitudinally or along an imaginary central axis of the suction hose are preferably referred to as flow elements that run transversely to the extruder or winding profile of the suction hose. Tests have shown that such structural elements on the inside of the suction hose that run transversely to the extruder or winding profile of the suction hose allow the air flow to assume an essentially spiral shape, which can preferably be single-threaded or multi-threaded.Similar to multi-start threads, the suction hose can comprise more than one spiral thread, with the individual spiral threads preferably running essentially parallel to each other. The pitches of the individual spirals are preferably the same.
[0018] A similarly positive effect on energy losses from a fluid mechanics perspective can also be observed with structural elements, which can, for example, be formed as essentially circular depressions and arranged on the flat sections. Such essentially circular depressions also preferably have a significantly shallower depth than the protrusions, whereby the air flow, after leaving these depressions, is carried over the deeper protrusions and thus prevented from penetrating the protrusions.
[0019] The embossed flow geometry can preferably also imitate the structure of shark skin. In the context of the invention, this preferably means that scale-like structural elements are embossed, particularly on the flat sections of the inner profile, which can positively influence the internal flow properties of the suction hose. In other words, the suction hose can have an embossed flow geometry, wherein the flow geometry has scale-like structural elements that are based on the structure of a shark's skin. By imitating the properties of shark skin through the embossed flow geometry, the flow resistance of the main flow can advantageously be reduced.
[0020] Within the meaning of the invention, it may be preferred for the flow geometry to run substantially transversely to an imaginary central axis of the suction hose. Flow elements that run substantially transversely to an imaginary central axis of the suction hose can, for example, be transverse grooves that can run on the flat sections of the inner profile. The at least one transverse groove can run substantially parallel to the adjacent protrusions of the inner profile of the suction hose. Preferably, the transverse groove also has a significantly smaller depth than a protrusion. The transverse grooves preferably run substantially perpendicular to a central axis of the suction hose.The air flow can penetrate the transverse grooves. It has been shown that flowing out of a transverse groove also acts as a ski jump for the air flow, so that the air flow, after crossing the transverse groove, jumps over the subsequent protrusion and thus does not penetrate, or only to a very limited extent, into the protrusion of the inner profile of the suction hose. This advantageously influences the boundary layers of the main flow, reducing the secondary flow and generating less turbulence locally. Tests have shown that the provision of the imposed flow geometry can reduce, in particular, the wall shear stress in the suction hose and the flow resistance.
[0021] As a result, by providing flow elements that run essentially transversely to an imaginary central axis of the suction hose, the turbulence that occurs in conventional suction hoses without flow elements can be significantly reduced. Within the meaning of the invention, it is preferred that flow elements that run essentially transversely to an imaginary central axis of the suction hose be referred to as flow elements that run longitudinally or along the extruder or winding profile of the suction hose. Tests have shown that such structural elements on the inside of the suction hose that run longitudinally to the extruder or winding profile of the suction hose can direct the air flow towards a central region of the suction hose. This gives the flow a particularly laminar character and flows particularly smoothly and without turbulence.In particular, this avoids unwanted turbulence in the area of the protrusions on the inside of the suction hose.
[0022] It may also be preferred within the meaning of the invention for the flow geometry to have at least one groove, wherein the at least one groove forms an angle with a central axis of the suction hose. Within the meaning of the invention, this preferably means that the at least one groove runs obliquely on the flat section of the inner profile. As a result, the at least one groove can form a spiral running circumferentially on the flat sections, so that the air flow can be guided along this circumferential groove. Tests have shown that a suction hose with particularly good flow properties can be provided if the suction hose has at least one circumferential groove for guiding the air flow.Preferably, a flow geometry with a spiral groove can be composed of individual sections formed by grooves that run diagonally on the flat sections of the inner profile of the suction hose and / or form an angle with the central axis of the suction hose. Such a spiral groove as a structural element of the flow geometry locally disrupts the vortices of the secondary flow present in the protrusions at the points where the longitudinal groove meets the protrusions. These vortices are crucial for the hose's energy losses. Penetrating the vortices in the protrusions causes them to be noticeably disrupted in their structure and thus also lose their intensity.
[0023] In order to reduce the flow and energy losses that occur when an air flow passes through a suction hose, it is preferred according to the invention to introduce or provide so-called "direct structural elements" on an inner side of the suction hose. The direct structural elements are preferably designed to reduce secondary flow within the air flow through the suction hose. Direct structural elements according to the invention are, for example, grooves that can run parallel to the central axis of the suction hose or with a pitch angle on the inner side of the suction hose. The grooves differ from the mutually parallel grooves or protrusions that the suction hose has due to its manufacturing process. According to the invention, it is preferred for the direct structural elements to run transversely to the grooves and / or protrusions.In the context of the invention, this preferably means that the direct structural elements penetrate the grooves and / or protrusions in such a way that they intersect them or do not run parallel to them. Tests have shown that by penetrating the grooves and / or protrusions with the direct structural elements, the secondary flow within the air stream through the suction hose can be reduced, allowing the air stream to flow through the suction hose with less loss.
[0024] Alternatively or additionally, so-called "hybrid structural elements" can be provided within the suction hose, with which both the secondary flow and the main air flow within the suction hose can be influenced in order to reduce the flow and energy losses of the air flow. Hybrid structural elements can, for example, be modifications to the inner surface of the suction hose, which can preferably be arranged on the flat sections between the grooves and protrusions on the inside of the suction hose. For example, the surface of these flat sections can be shaped similarly to shark skin or have small dents or depressions, like the surface of a golf ball.Tests have shown that the hybrid structural elements can influence both the main air flow and the secondary flow within the suction hose, so that the provision of these hybrid structural elements can particularly effectively reduce the flow and energy losses within the air flow.
[0025] In a second aspect, the invention relates to a method for producing a suction hose. The terms, definitions, and technical advantages introduced for the suction hose preferably apply analogously to the manufacturing method. The method for producing the suction hose is characterized by the following process steps: a) extruding a material strand, b) cooling the material strand, c) processing the material strand to obtain the inner profile of the suction hose, in particular winding it, d) incorporating the flow geometry and / or its structural elements into the material strand and / or the inner profile of the suction hose in a modification phase.
[0026] During extrusion, the base material of the future suction hose is pressed out of a shaping opening, so that a shaped mass is obtained as a so-called extrudate. The shaping opening can be designed as a nozzle or as a so-called mouthpiece. Extrusion can in particular take place under pressure. In the proposed manufacturing process, the extrudate is in particular in the form of a wound profile, which can have a spiral or wave shape. In the sense of the invention, it is preferred that the cooling of the material strand in the proposed manufacturing process takes place in a fluid, wherein water, for example, can be used as the fluid. However, air cooling can also be provided.The extruded material strand, which preferably has the shape of a wound profile with protrusions and flat sections, can be cooled in a water bath after leaving the extruder or the resulting wound profile can be rinsed or sprayed with cooling water to achieve a cooling effect.
[0027] It should be noted that the proposed manufacturing process does not have to be carried out in the order presented above. Expediently, the material strand is first pressed out of the nozzle and / or the mouthpiece. However, the order of the above-mentioned process steps b) to d) can be varied. Deviating from the order presented above, the material strand can also be wound up first and then cooled. The introduction of the flow geometry and / or its structural elements into the material strand can also take place, for example, before winding and / or before cooling of the material strand. If the introduction of the flow geometry and / or its structural elements into the material strand takes place before cooling of the material strand, this is preferably referred to as a first modification phase within the meaning of the invention.If the flow geometry and / or its structural elements are introduced after the material strand has cooled, this is preferably referred to as a second modification phase within the meaning of the invention. In addition to winding, "processing" the material strand can also include welding or gluing, or the application of another joining technique. It may also be preferred within the meaning of the invention for the material strand or the resulting wound profile to be trimmed or cut to shape. This allows, in particular, the length of the suction hose to be varied.
[0028] In the context of the invention, it is provided that the flow geometry or the structural elements that form the flow geometry are introduced into the future suction hose in a so-called modification process step. The proposed manufacturing method can preferably comprise one or more modification steps, which are carried out, for example, before or after cooling the material strand. The introduction of the flow geometry and / or its structural elements is preferably carried out by incorporating or imprinting the flow geometry and / or its structural elements into the material strand and / or into the winding profile of the suction hose.
[0029] According to the invention, it is preferred that the flow geometry is introduced into the material strand in a first modification phase and / or into the inner profile of the suction hose in a second modification phase, the first modification phase occurring between the extrusion and cooling of the material strand, and the second modification phase occurring after the material strand has been wound up. According to the invention, this preferably means that the flow geometry can be introduced into the material strand in a first modification phase, this first modification phase occurring between the extrusion and cooling of the material strand. Alternatively or additionally, the flow geometry or its structural elements can be introduced into the inner profile of the suction hose in a second modification phase, this second modification phase occurring after the material strand has been wound up.
[0030] Within the meaning of the invention, it is particularly preferred that longitudinal grooves, transverse grooves, circumferential spiral grooves, depressions, and / or scale-like structural elements can be introduced into the future suction hose through the step of indentation or embossing. These structural elements are advantageously designed to influence the flow behavior of the air flow through the suction hose. Preferably, the structural elements have a positive fluid-mechanical effect on energy losses in that the air flow is prevented by the structural elements from penetrating the protrusions of the inner profile of the suction hose. The "jumping" of the air flow over the protrusions is also preferably referred to within the meaning of the invention as "aerodynamic overflow of a protrusion."The inventors have recognized that this penetration of the air flow into the protrusions on the inside of the suction hose, which are present due to the manufacturing process, can be a significant cause of undesirable turbulence and vortexes within the suction hose. With the invention, in particular by providing the flow geometry and / or its structural elements, the penetration of the air flow into the protrusions on the inside of the suction hose can be advantageously significantly prevented. This allows the air flow within the suction hose to be calmed in the sense that turbulence and vortexes can be significantly reduced and the flow efficiency within the suction hose can be significantly improved.
[0031] Further advantages emerge from the following description of the figures. The figures, the description, and the claims contain numerous features in combination. Those skilled in the art will expediently consider the features individually and combine them into further meaningful combinations. In the figures, identical and similar components are numbered with the same reference numerals.
[0032] They show:
[0033] Fig. 1 View of a preferred embodiment of a structural unit of the suction hose, wherein the structural unit comprises a flat section and a protuberance
[0034] Fig. 2 schematic view of a preferred embodiment of the suction hose Fig. 3 view of preferred embodiments of structural elements of the flow geometry
[0035] Fig. 4 Representation of the flow effect caused by the flow geometry
[0036] Fig. 5 View of a spiral flow geometry Fig. 6 View of a flow geometry with scale-like structural elements
[0037] Implementation examples and figure descriptions:
[0038] Figure 1 shows a preferred embodiment of a structural unit 26 of the suction hose 10 (cf. Figure 2), wherein the structural unit 26 comprises a flat section 24 and a protuberance 22. The suction hose 10 is preferably composed of structural units 26, wherein flat sections 24 and protuberances 22 alternate. The flat sections 24 and the protuberances 22 form the inner profile 20 of the suction hose 10, wherein the inner profile 20 is preferably also referred to as a wound or extruded profile within the meaning of the invention. The flat sections 24 and the protuberances 22 are arranged at regularly repeating intervals. In the area of the protuberances 22, the suction hose 10 expands so that the air flow 70, which flows through the suction hose 10 if no countermeasures are taken, can flow into the protuberances 22.This can lead to undesirable eddies and turbulence in the air flow 70, which can negatively impact the flow efficiency of the air flow 70. To avoid the undesirable eddies and turbulence in the air flow 70, the proposed suction hose 10 has an embossed flow geometry 30 with structural elements 50 (see Figure 3), which advantageously result in the protrusions 22 being aerodynamically flowed over.
[0039] As a result, the air flow 70 can flow through the suction hose 10 much more efficiently thanks to the invention.
[0040] Figure 2 shows a schematic view of a preferred embodiment of the suction hose 10. The suction hose 10 is obtained by extrusion from a material strand 60 and is composed of structural units 26. The structural units 26 comprise flat sections 24 and protrusions 22, which alternate to form the suction hose 10. This gives the suction hose 10 its spiral or wave shape. Furthermore, in Figure 2, the imaginary central axis 40 is represented by the suction hose 10. The structural elements 50 of the flow geometry 30 can be arranged longitudinally or transversely to this imaginary central axis 40. Alternatively or additionally, the structural elements 50 of the flow geometry 30 can enclose an angle with the imaginary central axis 40. In this case, the structural elements 50, which can be designed as grooves, for example, can run obliquely on the flat sections 24 of the inner profile 20 of the suction hose 10.According to the invention, it is preferred that structural elements 50 that run longitudinally to the imaginary central axis 40 of the suction hose 10 run transversely to the inner or wound profile 20 of the suction hose 10, and vice versa. The suction hose 10 preferably has a circular base area, which is visible, for example, in a sectional view of the suction hose 10. The imaginary central axis 40 of the suction hose 10 preferably runs through the center of this circular base area.
[0041] The suction hose 10 can, for example, be connected to a vacuum cleaner (not shown) to suck in dust. In particular, the suction hose 10 can be connected to a machine tool (not shown) to suck in dust or particles that arise in a work area of the machine tool when working with the machine tool.
[0042] Figure 3 shows various configurations of structural elements 50 of the flow geometry 30 of the suction hose 10. The structural elements 50 form a flow geometry 30 that is embossed into the base material or material strand 60 of the suction hose 10 during the manufacturing process. The structural elements 50 can be designed as longitudinal grooves 54 (see partial figure 3a), depressions 58 (see partial figure 3b), transverse grooves 52 (see partial figure 3c), and / or as spiral grooves 56 (see partial figure 3d). The structural elements 50 are arranged in particular on the flat sections 24 of the inner profile 20 of the suction hose 10. The partial figures 3a, 3b and 3c show oblique views of a structural unit 26 of the inner profile 20 of the suction hose 10, while the partial figure 3d shows a plan view of a structural unit 26.The flat section 24 and the protrusion 22 of the structural unit 26, as well as the arrangement of the spiral groove 56 of the flow geometry 30, are shown from above. The recesses 58, shown in Figure 3b, are similar to the recesses of a golf ball. Tests have shown that a flow geometry 30 comprising such substantially circular recesses 58 as structural elements 50 is particularly well suited to calming an air flow 70 and improving flow efficiency within the suction hose 10.
[0043] Figure 4 shows the flow effect on the air flow 70 that can be caused by the imposed flow geometry 30 of the suction hose 10. The structural elements 50 of the flow geometry 30 cause a ski jump effect, which causes the air flow 70 to lift off the flat section 24 of the inner profile 20. As a result, the air flow 70 "flies" over the subsequent protrusion 22 and is, in particular, prevented from penetrating the protrusion 22. In this way, the air flow 70 within the suction hose 10 can be considerably calmed. Advantageously, the provision of the flow geometry 30 or its structural elements 50 can ensure that the air flow 70 aerodynamically flows over the protrusions 22 of the suction hose 10.
[0044] Figure 5 shows a view of a flow geometry 30 with a spiral groove 56 as a structural element 50. The "spiral" is particularly evident when the course of the grooves 56 is observed on the flat sections 24 of the suction hose 10. Such a top view of a structural unit 26 of the suction hose 10 is shown, for example, in sub-figure 3d.
[0045] Figure 6 shows a flow geometry 30 with scale-like structural elements 59. Such scale-like structural elements 59 are preferably designed to replicate the structure of a shark skin. Tests have shown that a flow geometry 30 which is
[0046] Structure resembling a shark skin, is particularly well suited to calming an air flow 70 and improving the flow efficiency of the air flow 70 within the suction hose 10.
[0047] 15 List of reference symbols
[0048] 10 suction hose
[0049] 20 inner profile
[0050] 22 protrusion
[0051] 24 flat section
[0052] 26 structural unit
[0053] 30 Flow geometry
[0054] 40 imaginary central axis of the suction hose
[0055] 50 Structural element of flow geometry
[0056] 52 Longitudinal groove
[0057] 54 Quemut
[0058] 56 spiral groove
[0059] 58 essentially circular depressions
[0060] 59 scale-like structural elements
[0061] 60 material strands
[0062] 70 air flow
Claims
Patent claims 1 . Suction hose (10) for a vacuum cleaner, characterized in that the suction hose (10) has, due to its manufacturing process, an inner profile (20) with protuberances (22) and flat sections (24) repeated at regular intervals, wherein the inner profile (20) has an embossed flow geometry (30) for flowing over the protuberances (22).
2. Suction hose (10) according to claim 1, characterized in that the flow geometry (30) is arranged in the region of the flat sections (24) of the inner profile (20) of the suction hose (10).
3. Suction hose (10) according to claim 1 or 2, characterized in that the flow geometry (30) comprises at least one structural element (50) per flat section (24).
4. Suction hose (10) according to one of the preceding claims, characterized in that the flow geometry (30) runs substantially longitudinally or transversely to an imaginary central axis (40) of the suction hose (10).
5. Suction hose (10) according to one of the preceding claims, characterized in that the flow geometry (30) has as a structural element (50) at least one longitudinal groove (52) per flat section (24).
6. Suction hose (10) according to one of the preceding claims, characterized in that the flow geometry (30) has a plurality of structural elements (58, 59) per flat section (24). Suction hose (10) according to one of the preceding claims, characterized in that the flow geometry (30) has at least one transverse groove (54) as a structural element (50). Suction hose (10) according to one of the preceding claims, characterized in that the flow geometry (30) has at least one spiral groove (56) as a structural element (50). Suction hose (10) according to one of claims 3 to 8, characterized in that the structural elements (50) are formed by substantially circular depressions (58) and / or as scale-like structural elements (59). Method for producing a suction hose (10) according to one of the preceding Claims characterized by the following method steps: a) extruding a material strand (60), b) cooling the material strand (60), c) processing the material strand (60) to obtain the inner profile (20) of the suction hose (10), in particular winding it up, d) introducing the flow geometry (30) and / or its structural elements (50) in a modification phase into the material strand (60) and / or into the inner profile (20) of the suction hose (10). Method according to claim 10, characterized in that the introduction of the flow geometry (30) takes place in a first modification phase into the material strand (60) and / or in a second modification phase into the inner profile (20) of the suction hose (10), wherein the first modification phase lies between the extrusion and the cooling of the material strand (60) and the second modification phase lies after the winding of the material strand (60).