Suction hose for vacuum cleaner and method for manufacturing same

Abstract

The invention relates to a suction hose for a vacuum cleaner, in which, as a result of manufacture, the suction hose has an inner contour with protrusions and flat portions repeating at regular intervals. The inner contour of the suction hose has an embossed flow geometry for air to flow through the protrusions. Due to this flow effect, vortices and turbulence in the suction hose can be greatly reduced, and the flow behavior inside the suction hose can become more laminar, and the loss is lower. In a second aspect, the invention relates to a method for manufacturing such a suction hose.

Description

Technical Field

[0001] The invention relates to a suction hose for a vacuum cleaner, wherein, as a result of production, the suction hose has an inner profile with projections and flat parts that are repeated at regular intervals. The inner profile of the suction hose has an embossed flow geometry for the air to flow through the projections. Due to this flow influence, eddies and turbulence in the suction hose can be significantly reduced and the flow behavior inside the suction hose can become more laminar and with lower losses. In a second aspect, the invention relates to a method for producing such a suction hose. Background Art

[0002] In the field of vacuum cleaners, it is known that suction hoses usually have a spiral or corrugated form. For structural reasons, these suction hoses have protrusions repeated at regular intervals, wherein these protrusions may hinder the desired laminar (i.e., stratified) form of air flow in the suction hose. On the contrary, the protrusions cause eddies, thereby introducing turbulence into the air flow, which may produce flow and energy losses, which is very unfavorable. This turbulence and these losses may have a negative impact on the system efficiency and / or flow efficiency of the suction hose. The protrusions in the suction hose can also be described as grooves, wherein the grooves may cause the losses in the suction hose. In particular, due to flow resistance, friction losses occur in the region of the main airflow inside the suction hose. However, in the secondary flow inside the suction hose, the losses are mainly caused by the energy input into the lateral vortex.

[0003] The suction hose comprises in particular a spiral groove, wherein the spiral pitch is usually constant. The area between the groove turns is continuously interconnected and flat, and is referred to as a "flat portion" in the context of the present invention. In a horizontal section through the axis of the suction hose, the cross-sectional plane contains a structure repeated at regular intervals. In each case, the protrusions and the flat portion preferably form a structural unit, wherein the suction hose comprises a successive structural unit. When air flows through these protrusions (preferably constituting a local cross-sectional change in the suction hose), as the main airflow or primary airflow inside the suction hose, turbulence may be formed in the area of ​​these protrusions, which is also preferably described as a secondary flow in the sense of the present invention. Disadvantageously, the vortex generated may cause disturbances in the boundary layer of the airflow inside the suction hose. For example, compared with the ideal geometry of a smooth tube with constant size (as a reference), the combination of these individual vortices and the additional turbulence generated by these vortices may cause very high flow and energy losses. These losses may accordingly have a perceptible impact on the system efficiency and / or flow efficiency of the suction hose.

[0004] The cross-sectional changes in the flow geometry caused by the grooves perpendicular to the main flow usually cause secondary flows within the air flow in the suction hose, which secondary flows are preferably oriented substantially perpendicular to the main flow. The speed of the associated vortices is low compared to the speed of the main flow, but when they occur in large numbers (as in the suction hose), i.e. frequently, they can extract considerable energy from the flow system. The vortices (preferably caused by the cross-sectional changes associated with the grooves or protrusions) may form a spiral secondary flow in the protrusions or grooves, which is oriented perpendicular to the main flow of the air flow in the suction hose.

[0005] In order to avoid such eddies or turbulences, the prior art has proposed at least partially filling the protrusions. For example, DE10 2011 084 195 B4 proposes using compressible foam to fill the shallow grooves of the hose profile. However, the disadvantage of filling the shallow grooves may be the degradation of the inherent advantageous mechanical properties of the spiral or corrugated suction hose (such as robustness and stability). In addition, these at least partially filled shallow grooves or protrusions may accumulate dust more easily, which often hinders the maintenance of the suction hose.

[0006] Furthermore, the prior art has proposed to provide flow bodies in the interior of the suction hose in order to improve the flow behavior of the air-dust mixture in the suction hose. However, the introduction of such flow bodies in the interior of the suction hose is complicated and expensive, and the flow bodies protruding inwards into the suction hose reduce the flow cross section. As a result, a suction hose constructed in this way can become particularly susceptible to clogging.

[0007] The object on which the present invention is based is to overcome the above-mentioned drawbacks and disadvantages of the prior art and to provide a suction hose which has a high flexibility, which at the same time has a high wear resistance and stability and which is also easy to clean and maintain. In addition, the suction hose to be produced has favorable internal flow properties, so that the suction flow can flow through the suction hose with minimal losses in order to achieve high system and flow efficiencies. Another focus of the present invention is to provide a method for producing such a suction hose.

[0008] This object is achieved by the subject matter of the independent claims. Advantageous embodiments related to the subject matter of the independent claims are found in the dependent claims. Summary of the invention

[0009] According to the invention, a suction hose for a vacuum cleaner is provided. As a result of the manufacture, the suction hose has an internal profile with ridges and flat sections that are repeated at regular intervals, wherein the internal profile has an embossed flow geometry for air to flow through the ridges. The ridges and flat sections of the suction hose are particularly clearly shown in the accompanying drawings. In the sense of the invention, it is preferred that the suction hose is spiral or corrugated and is thereby particularly flexible, but also wear-resistant and stable. The spiral or corrugated design is achieved by the proposed suction hose, which has ridges and flat sections that are repeated at regular intervals. In each case, the ridges and flat sections can form structural units of the suction hose, wherein these structural units are repeated at regular intervals and thus produce a corrugated or spiral form of the suction hose. According to the invention, it is preferred that the suction hose is configured as a spiral suction hose, wherein the ridges have a substantially constant pitch. This basic structure of the suction hose is preferably referred to as a "corrugated or spiral form of the suction hose".

[0010] During the operation of the vacuum cleaner, due to the decompression inside the vacuum cleaner, the air-dust mixture is sucked through the suction hose. Thus, an airflow is formed, which is preferably directed mainly from the front area of ​​the suction hose towards the main body of the vacuum cleaner. For the purposes of the present invention, this airflow 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 nozzle or a floor nozzle for sucking in dust. In the sense of the present invention, it can also be preferred that the front area of ​​the suction hose is connected to a machine tool in order to suck in dust generated during the operation of the machine tool and store the dust inside the vacuum cleaner.

[0011] The projections or grooves constitute cross-sectional changes of the suction hose. As a side effect of these cross-sectional changes (preferably extending substantially perpendicularly to the main flow), undesirable energy-consuming helical secondary flows are generated in these projections.

[0012] In contrast, the airflow of dust-air mixture can flow away in a substantially laminar and uniform manner on the flat part of the profile. In the area of ​​the protrusion, the space available for the airflow increases, and turbulence (particularly secondary flow) of the airflow can occur. In order to reduce the occurrence and negative flow effects of the protrusion and the associated turbulence, in the context of the present invention, it is proposed that the internal profile of the suction hose has a flow geometry, wherein it has been found that the proposed flow geometry with regularly repeated protrusions and flat parts advantageously causes aerodynamic flow on the protrusion. In the context of the present invention, the phrase "aerodynamic flow" preferably refers to the flow on the protrusion to occur with minimal energy loss. As a result, significantly less eddy and less turbulence occur in the airflow in the suction hose, and the system efficiency and flow efficiency of the proposed suction hose are significantly increased, because the flow loss and pressure loss can be significantly reduced. Tests have shown that when the flow geometry is provided, less dust is settled in the protrusion, so that even after a long period of use, the protrusion is only slightly filled. In this way, the suction hose maintains its favorable mechanical properties, such as flexibility and stability. Furthermore, the proposed suction hose has proven to be particularly wear-resistant and requires little maintenance.

[0013] The flow geometry of the inner contour 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 plastic. Due to the embossing of the flow geometry into the base material of the suction hose, a particularly advantageous suction hose can be obtained and a particularly cost-effective method for producing the suction hose is provided, since the provision of a complex flow body on the inner side of the suction hose can be omitted.

[0014] In the context of the present invention, it is preferred that the flow geometry or its structural elements are arranged in the region of the flat parts of the inner contour of the suction hose. The flow geometry can include at least one structural element on each flat part, so that the flow geometry can consist of one structural element or several structural elements. The structural elements of the flow geometry are preferably arranged in the region of the flat parts of the inner contour of the suction hose. Tests have shown that as a result, the air can flow particularly well over the protrusions of the inner contour. In particular, the air flow does not penetrate deeply into the protrusions, so that turbulence can be avoided particularly effectively. In particular, the air flow over the protrusions can be particularly good with respect to minimizing secondary flows.

[0015] In the context of the present invention, it may be preferred that the flow geometry extends substantially along the theoretical center axis of the suction hose. For example, the flow geometry may have at least one longitudinal groove on each flat portion. At least one longitudinal groove may extend, for example, on a flat portion. Here, at least one longitudinal groove may extend substantially perpendicular to an adjacent protrusion of the inner contour of the suction hose. Preferably, the longitudinal groove has a significantly smaller depth than the protrusion. In the context of the present invention, this preferably means that the protrusion is formed to be significantly deeper than the longitudinal groove. The longitudinal groove preferably extends substantially parallel to the center axis of the suction hose. The airflow may penetrate into the longitudinal groove and interrupt the secondary flow at the interface with the groove. These constant interruptions in the spiral vortex inside the suction hose significantly reduce the intensity of the secondary flow.

[0016] Thus, the turbulence that occurs in a conventional suction hose without a flow element can be significantly reduced. In the context of the present invention, the longitudinal groove constitutes a flow element or a structural element extending substantially along or parallel to the theoretical center axis of the suction hose. In the context of the present invention, it is preferred that the flow element extending substantially along or parallel to the theoretical center axis of the suction hose is described as a flow element extending transversely to the extrusion or winding profile of the suction hose in the sense of the present invention. Tests have shown that, due to the extension of these structural elements on the inner side of the suction hose transversely to the extrusion or winding profile of the suction hose, the airflow can present a substantially spiral form, which form can preferably have one or more turns. Like a multi-turn thread, the suction hose can include more than one turn, wherein the individual turns of the spiral preferably extend substantially parallel to each other. The pitch of each turn is preferably the same.

[0017] Another aerodynamically positive influence on the energy losses can also be observed for structural elements which can be formed, for example, as substantially circular depressions and are arranged on the flat portion. These substantially circular depressions preferably also have a significantly smaller depth than the projections, wherein after leaving these depressions, the airflow is carried away via the deeper projections and in this way prevented from penetrating into the projections.

[0018] The embossed flow geometry can also preferably imitate the structure of shark skin. In the context of the present invention, this preferably means that scale-like structural elements that can positively influence the internal flow properties of the suction hose are embossed onto the flat part of the inner contour. In other words, the suction hose can have an embossed flow geometry, wherein the flow geometry has scale-like structural elements based on the structure of shark skin. By imitating the properties of shark skin, the embossed flow geometry can advantageously reduce the flow resistance of the main flow.

[0019] In the context of the present invention, it may be preferred that the flow geometry extends substantially transversely to the theoretical center axis of the suction hose. The flow element extending substantially transversely to the theoretical center axis of the suction hose may be, for example, a transverse groove, which may extend on the flat part of the inner profile. Here, at least one transverse groove may extend substantially parallel to the adjacent protrusion of the inner profile of the suction hose. Preferably, the transverse groove has a depth significantly smaller than the protrusion. The transverse groove preferably extends substantially perpendicular to the central axis of the suction hose. The airflow may penetrate into the transverse groove, wherein it has been found that the outlet from the transverse groove also acts as a ski jump for the airflow, so that after passing through the transverse groove, the airflow jumps over the next protrusion, and therefore does not penetrate (or only penetrates to a lesser extent) into the protrusion of the inner profile of the suction hose. Therefore, the boundary layer of the mainstream can be advantageously affected, so that the secondary flow is first reduced, and less turbulence is generated locally secondarily. Tests have shown that by providing an embossed flow geometry, the wall shear stress and flow resistance in the suction hose can be reduced in particular.

[0020] Therefore, providing a flow element extending substantially transversely to the theoretical center axis of the suction hose can significantly reduce the turbulence that occurs in a conventional suction hose without a flow element. In the context of the present invention, it is preferred that the flow element extending substantially transversely to the theoretical center axis of the suction hose is described in the sense of the present invention as a flow element extending along or parallel to the extrusion or winding profile of the suction hose. Tests have shown that, since such structural elements extend parallel to the extrusion or winding profile of the suction hose on the inner side of the suction hose, the air flow can be carried out in the direction of the central area of ​​the suction hose. Therefore, the flow has very strong laminar characteristics, and the flow is particularly smooth and without turbulence. In particular, the occurrence of undesirable vortices in the raised area inside the suction hose is avoided in this way.

[0021] In this sense of the invention, it can also be preferred that the flow geometry comprises at least one groove, wherein the at least one groove is angled with the central axis of the suction hose. In the context of the present invention, this preferably means that at least one groove extends obliquely on the flat part of the inner contour. Therefore, at least one groove can form a circumferential spiral on the flat part, so that the airflow can be guided along the circumferential groove. Tests have shown that if the suction hose has at least one circumferential groove for guiding the airflow, a suction hose with particularly good flow characteristics can be provided. Preferably, the flow geometry with helical grooves can be composed of individual parts formed by grooves, which extend obliquely on the flat part of the contour of the suction hose and / or are angled with the central axis of the suction hose. Such spiral grooves as structural elements of the flow geometry locally interrupt the vortex of the secondary flow in the protrusion at the point where the longitudinal groove meets the protrusion. These vortices are decisive for the energy loss of the hose. Such interruption of the vortex in the protrusion can cause substantial damage to the structure of the vortex, causing them to lose strength.

[0022] In order to reduce the flow loss and energy loss that occur when the airflow passes through the suction hose, in the context of the present invention, it is preferred to introduce or provide a so-called "direct structural element" on the inner side of the suction hose. The direct structural element is preferably designed to reduce the secondary flow in the airflow passing through the suction hose. The direct structural element in the sense of the present invention is, for example, a groove, which can extend parallel to the central axis of the suction hose or extend at a pitch angle on the inner side of the suction hose. These grooves are different from the mutually parallel grooves or protrusions that form the suction hose during manufacturing. In the context of the present invention, it is preferred that the direct structural element extends transversely to the grooves and / or protrusions. In the context of the present invention, this preferably means that the direct structural element interrupts the grooves and / or protrusions because the direct structural element intersects with the grooves and / or protrusions or is not exactly parallel to the grooves and / or protrusions. Tests have shown that this interruption of the grooves and / or protrusions by the direct structural element can reduce the secondary flow in the airflow passing through the suction hose, so that air can flow through the suction hose with lower losses.

[0023] Alternatively or additionally, a so-called "mixing structural element" can be arranged inside the suction hose, which can preferably affect both the secondary flow inside the suction hose and the primary airflow, so as to reduce the flow losses and energy losses of the airflow. The mixing structural element can, for example, be a modification of the inner surface of the suction hose, which can preferably be arranged on the flat parts between the grooves and the protrusions on the inner side of the suction hose. For example, the surface of these flat parts can be configured to be similar to shark skin, or have small dimples or pits like the surface of a golf ball.

[0024] Tests have shown that mixing structural elements can influence both the primary air flow and the secondary flow inside the suction hose, so that by providing these mixing structural elements flow losses and energy losses within the air flow can be reduced particularly well.

[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 in an analogous manner to the proposed production method. The method for producing a suction hose is characterized by the following method steps:

[0026] a) extruding a strip of material,

[0027] b) cooling the strip of material,

[0028] c) processing the material strip, in particular winding it, to produce the inner contour of the suction hose,

[0029] d) In a modification phase, flow geometries and / or structural elements thereof are introduced into the inner contour of the material strip and / or the suction hose.

[0030] During extrusion, the base material of the rear suction hose is squeezed through the forming opening so as to give a formed mass as an extruded product. The forming opening can be configured as a nozzle or a mouthpiece. The extrusion can occur in particular under pressure. In the proposed manufacturing method, the extruded product in particular takes the form of a winding profile, which can have a spiral or corrugated form. In the context of the present invention, it is preferred that the material strip is cooled in a fluid in the proposed manufacturing method, wherein the fluid can be, for example, water. However, air cooling can also be provided. The extruded material strip (preferably in the form of a winding profile with protrusions and flat parts) can be cooled in a water bath after leaving the extruder, or the resulting winding profile can be rinsed or sprayed with cooling water in order to achieve a cooling effect.

[0031] It should be noted that the proposed manufacturing method does not need to be carried out in the order given above. It is suitable that the material strip is first squeezed through a nozzle and / or a mouthpiece. However, the order of the above method steps b) to d) can be changed. By deviating from the above order, the material strip can be first wound and then cooled. Moreover, the introduction of flow geometry and / or structural elements into the material strip can occur, for example, before the winding material strip and / or before the cooling material strip. If the flow geometry and / or structural elements are introduced into the material strip before the cooling material strip, then in the context of the present invention, this is preferably described as the first modification stage. If the flow geometry and / or structural elements are introduced after the cooling material strip, then in the context of the present invention, this is preferably described as the second modification stage. The "processing" of the material strip can include not only winding but also welding or gluing, or using another joining method. It can also be preferred in the sense of the present invention that the material strip or the resulting winding profile is directly cut into a certain size or shape. Therefore, in particular, the length of the suction hose can be changed.

[0032] In the context of the invention, it is proposed that in a so-called modification method step, a flow geometry or a structural element forming the flow geometry is introduced into the future suction hose. The proposed production method can preferably include one or more modification steps, which are carried out, for example, before or after the material strip has cooled. The introduction of the flow geometry and / or its structural elements is preferably achieved by embossing or stamping the flow geometry and / or its structural elements into the winding profile of the material strip and / or the suction hose.

[0033] In the context of the present invention, it is preferred that the flow geometry is introduced into the material strip in a first modification phase and / or into the inner contour of the suction hose in a second modification phase, wherein the first modification phase is temporally between extrusion and cooling of the material strip and the second modification phase is temporally after the winding of the material strip. In the context of the present invention, this preferably means that the flow geometry can be introduced into the material strip in a first modification phase, wherein the first modification phase is temporally between extrusion and cooling of the material strip. Alternatively or additionally, the flow geometry or its structural elements can be introduced into the inner contour of the suction hose in a second modification phase, wherein the second modification phase can be temporally after the winding of the material strip.

[0034] In the context of the present invention, it is very particularly preferred that the step of embossing or stamping allows the introduction of longitudinal grooves, transverse grooves, circumferential spiral grooves, pits and / or scale-like structural elements into the future suction hose. The structural element is advantageously designed to affect the flow behavior of the airflow through the suction hose. Preferably, the structural element has a positive aerodynamic effect on energy loss because the structural element prevents the airflow from penetrating into the protrusions of the inner contour of the suction hose. In the sense of the present invention, the "jump" of the airflow on the protrusion is preferably also described as "aerodynamic flow on the protrusion". The inventor has found that this airflow infiltration into the protrusions (generated during manufacturing) on ​​the inner side of the suction hose may be the substantial cause of the undesirable turbulence and eddy currents in the suction hose. The present invention (especially providing flow geometry and / or its structural elements) can advantageously significantly prevent the airflow from penetrating into the protrusions on the inner side of the suction hose. As a result, the airflow inside the suction hose can be stabilized because the turbulence and eddy current can be significantly reduced and the flow efficiency inside the suction hose can be significantly improved.

[0035] Additional advantages will become apparent from the following description of the drawings. The drawings, the specification and the claims contain many combined features. Those skilled in the art will also readily consider these features individually and combine them to form reasonable further combinations. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In the figures, identical and functionally identical components are denoted by the same reference symbols.

[0037] In the attached picture:

[0038] Figure 1 A view showing a preferred embodiment of a structural unit of a suction hose, wherein the structural unit comprises a flat portion and a projection,

[0039] Figure 2 A schematic diagram showing a preferred embodiment of a suction hose,

[0040] Figure 3 A view showing a preferred embodiment of a structural element of a flow geometry,

[0041] Figure 4 A diagram showing the flow effects caused by flow geometry,

[0042] Figure 5 A view showing the spiral flow geometry,

[0043] Figure 6 A view showing a flow geometry with scale-like structural elements. DETAILED DESCRIPTION

[0044] Figure 1A suction hose 10 is shown (see Figure 2 ) is a preferred embodiment of a structural unit 26, wherein the structural unit 26 comprises a flat portion 24 and a protrusion 22. The suction hose 10 is preferably composed of a structural unit 26, wherein flat portions 24 and protrusions 22 alternate. The flat portions 24 and the protrusions 22 form an inner profile 20 of the suction hose 10, wherein, in the context of the present invention, the inner profile 20 is preferably also referred to as a winding profile or an extruded profile. The flat portions 24 and the protrusions 22 are arranged at regularly repeated intervals. In the area of ​​the protrusions 22, the suction hose 10 widens, so that the air flow 70 flowing through the suction hose 10 can flow into the protrusions 22 unless countermeasures are taken. This may generate undesirable eddies and turbulence in the air flow 70, which may have a negative impact on the flow efficiency of the air flow 70. In order to avoid the generation of undesirable eddies and turbulence in the air flow 70, the proposed suction hose 10 has an embossed flow geometry 30, wherein there is a structural element 50 (see Figure 3 ), these structural elements advantageously generate a pneumatic flow over the protrusions 22. Thus, due to the invention, the air flow 70 can flow through the suction hose 10 significantly more efficiently.

[0045] Figure 2 A schematic diagram of a preferred embodiment of a suction hose 10 is shown. The suction hose 10 is obtained by extrusion from a material strip 60 and is composed of structural units 26. The structural unit 26 comprises flat portions 24 and protrusions 22, which alternate to form the suction hose 10. This gives the suction hose 10 a spiral or corrugated form. In addition, Figure 2 A theoretical center axis 40 is shown passing through the suction hose 10. The structural elements 50 of the flow geometry 30 can be arranged along or transversely to this theoretical center axis 40. Alternatively or additionally, the structural elements 50 of the flow geometry 30 can enclose an angle with the theoretical center axis 40. In this case, the structural element 50, which can be configured, for example, as a groove, can extend obliquely on the flat part 24 of the inner contour 20 of the suction hose 10. In the context of the present invention, it is preferred that the structural element 50 extending parallel to the theoretical center axis 40 of the suction hose 10 extends transversely to the inner contour or winding contour 20 of the suction hose 10, and vice versa.

[0046] The suction hose 10 preferably has a circular base surface, which is visible, for example, in a cross-sectional illustration of the suction hose 10. The theoretical center axis 40 of the suction hose 10 preferably extends through the center point of the circular base surface.

[0047] The suction hose 10 can be connected to a vacuum cleaner (not shown) for example 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 generated in the working area of ​​the machine tool when the machine tool is in use.

[0048] Figure 3 A number of different embodiments of structural elements 50 of the flow geometry 30 of the suction hose 10 are shown. The structural element 50 forms the flow geometry 30 which is embossed into the base material or material strip 60 of the suction hose 10 during the manufacturing process. The structural element 50 can be configured as a longitudinal groove 54 (see FIG. Figure 3 a), pit 58 (see Figure 3 b), transverse groove 52 (see Figure 3 c) and / or spiral groove 56 (see Figure 3 d). The structural element 50 is located in particular on the flat part 24 of the inner contour 20 of the suction hose 10. Figure 3 a. points Figure 3 b. Points Figure 3 c each shows an oblique view of the structural unit 26 of the profile 20 of the suction hose 10, while Figure 3 d shows a top view of the structural unit 26. The flat part 24 and the protrusions 22 of the structural unit 26 and the arrangement of the spiral grooves 56 of the flow geometry 30 are shown from above. Figure 3 The dimples 58 shown in b are formed like dimples of a golf ball. Tests have shown that a flow geometry 30 including such essentially circular dimples 58 as structural elements 50 is particularly suitable for smoothing the air flow 70 and increasing the flow efficiency inside the suction hose 10 .

[0049] Figure 4 The flow influence of the airflow 70 that may be caused by the embossed flow geometry 30 of the suction hose 10 is shown. The structural element 50 of the flow geometry 30 acts as a ski jump, so that the airflow 70 is separated from the flat part 24 of the inner contour 20. As a result, the airflow 70 "flies" over the subsequent protrusions 22 and is particularly prevented from penetrating into the protrusions 22. In this way, the airflow 70 inside the suction hose 10 can be substantially smooth. Advantageously, providing the flow geometry 30 or its structural element 50 can make the airflow 70 flow through the protrusions 22 of the suction hose 10 in an aerodynamic manner.

[0050] Figure 51 shows a view of a flow geometry 30 having spiral grooves 56 as structural elements 50 or the like. These "spirals" are particularly evident when observing the pattern of the grooves 56 on the flat part 24 of the suction hose 10. This top view of the structural unit 26 of the suction hose 10 is shown, for example, in FIG. Figure 3 d is shown.

[0051] Figure 6 A view of a flow geometry 30 with a scale-like structural element 59 is shown. Such a scale-like structural element 59 is preferably designed to imitate the structure of shark skin. Tests have shown that a flow geometry 30 with a structure similar to shark skin is particularly suitable for smoothing the airflow 70 and increasing the flow efficiency of the airflow 70 inside the suction hose 10.

[0052] List of Reference Numerals

[0053] 10 Suction hose

[0054] 20 Internal contour

[0055] 22 Bump

[0056] 24 Flat part

[0057] 26 structural units

[0058] 30 Flow Geometry

[0059] 40 Theoretical center axis of the suction hose

[0060] 50 Structural elements of flow geometries

[0061] 52 longitudinal grooves

[0062] 54 Horizontal groove

[0063] 56 Spiral groove

[0064] 58 Basically circular pit

[0065] 59 Squamous structural elements

[0066] 60 Material Strips

[0067] 70 Airflow

Claims

1. A suction hose (10) for a vacuum cleaner, It is characterized in that As a result of production, the suction hose (10) has an inner profile (20) with projections (22) and flat portions (24) repeated at regular intervals, wherein the inner profile (20) has an embossed flow geometry (30) for air to flow through the projections (22).

2. The suction hose (10) according to claim 1, It is characterized in that The flow geometry (30) is arranged in the region of a flat portion (24) of an inner contour (20) of the suction hose (10).

3. The suction hose (10) according to claim 1 or 2, It is characterized in that The flow geometry (30) includes at least one structural element (50) on each flat portion (24).

4. The suction hose (10) according to any one of the preceding claims, It is characterized in that The flow geometry (30) extends substantially along or transversely to a theoretical center axis (40) of the suction hose (10).

5. The suction hose (10) according to any one of the preceding claims, It is characterized in that The flow geometry (30) has at least one longitudinal groove (52) as a structural element (50) on each flat portion (24).

6. The suction hose (10) according to any one of the preceding claims, It is characterized in that The flow geometry (30) has a plurality of structural elements (58, 59) on each flat portion (24).

7. The suction hose (10) according to any one of the preceding claims, It is characterized in that The flow geometry (30) has at least one transverse groove (54) as a structural element (50).

8. The suction hose (10) according to any one of the preceding claims, It is characterized in that The flow geometry (30) has at least one spiral groove (56) as a structural element (50).

9. The suction hose (10) according to any one of claims 3 to 8, It is characterized in that These structural elements (50) are formed by essentially circular depressions (58) and / or as scale-like structural elements (59).

10. A method for producing a suction hose (10) as claimed in any one of the preceding claims, characterized in that The following method steps: a) extruding a strip of material (60), b) cooling the strip of material (60), c) processing, in particular winding, the material strip (60) to produce the inner contour (20) of the suction hose (10), d) In a modification phase, flow geometries (30) and / or structural elements (50) thereof are introduced into the inner contour (20) of the material strip (60) and / or the suction hose (10).

11. The method according to claim 10, It is characterized in that The flow geometry (30) is introduced into the material strip (60) in a first modification phase and / or into the inner contour (20) of the suction hose (10) in a second modification phase, wherein the first modification phase is located in time between extrusion and cooling of the material strip (60) and the second modification phase is located in time after winding of the material strip (60).

Images