EP3049677B1 - Suction device with sound reflector - Google Patents

Description

The invention relates to a suction device comprising a blower device for generating a suction air flow and an air guiding device which has at least one flow deflection element with an inlet pipe and an outlet pipe, the outlet pipe being oriented transversely to the inlet pipe.

Exhaust air, for example, is discharged via the flow deflection element. The exhaust air can be suction exhaust air and/or cooling exhaust air. Supply air can also be supplied via the flow deflection element.

From the U.S. 4,195,969 a vacuum cleaner is known which comprises a suction head. The suction head has a base, at least one fan motor disposed on the base and having an exhaust outlet. The exhaust air outlet is connected to a sound chamber in which a plurality of absorbing elements are positioned.

The invention is based on the object of providing a suction device of the type mentioned at the outset, which is designed to reduce noise with a low pressure drop in the air-guiding device.

This object is achieved according to the invention with the suction device mentioned at the outset in that a sound mirror device is arranged at a transition region between the inlet pipe and the outlet pipe, through which sound is reflected and/or sound is absorbed, the sound mirror device having a wall which reflects sound, that the wall comprises a first wall, which faces the inlet, that the wall comprises a second wall, which is oriented transversely to the first wall and connects to the first wall towards the inlet of the inlet pipe, that the wall has a third wall, which faces the first wall and connects the inlet pipe to the outlet pipe, wherein the third wall is curved, that an inner radius of the third wall is greater than half the hydraulic diameter of the inlet pipe, and that the inlet pipe has a first central longitudinal axis and the outlet pipe has a second central longitudinal axis, the first central longitudinal axis and the intersect the second central longitudinal axis at a point of intersection which lies in the transition region within the at least one flow deflection element.

Air flows through the flow deflection element, this flow being deflected at the flow deflection element.

By providing the sound mirror device, at least part of the sound waves is reflected within the flow deflection element. At least part of the corresponding sound waves cannot then pass through propagate an outlet of the outlet pipe and noise reduction is achieved accordingly.

The inlet at the inlet pipe and the outlet at the outlet pipe refer to sound propagation, i.e. sound enters the inlet pipe and exits from the outlet pipe. It is possible for a flow of fluid to also enter the inlet tube and exit the outlet tube. However, it is also possible for a fluid flow to enter the outlet tube and exit from the inlet tube.

The sound mirror device can be implemented in a simple manner by appropriate wall design. In particular, it can be designed in such a way that the flow is not influenced or is only influenced to a minimal extent.

The sound mirror device has a wall which reflects sound.

The wall is preferably oriented in such a way that a reflection direction points towards an inlet of the inlet pipe and/or that the wall is oriented in such a way that multiple sound reflections take place within the at least one flow deflection element. A noise reduction is then achieved.

The wall has a first wall facing the inlet. As a result, sound waves can be reflected in the direction of the first wall. As a result, the proportion of sound waves that can propagate through an outlet of the outlet pipe is reduced and noise reduction is achieved.

In one embodiment, a trough is formed at the transition area by the first wall. The trough forms a depression within the flow deflection element opposite the inlet. A "sound trough" is thereby formed in order to achieve effective noise reduction reach. The sound trough can have one or more straight or curved boundary walls.

In one embodiment, the first wall is at least approximately planar to effectively provide back reflection towards the inlet.

It is also advantageous if the first wall is oriented parallel to an inlet opening of an inlet or at a small acute angle of less than 30° to the inlet opening. This makes it possible to achieve effective back-reflection towards the inlet. If the first wall is oriented at a small acute angle to the inlet constriction, then a sound trough device can be realized. In this way, in particular, multiple reflections of sound waves can be achieved within the flow deflection element in order to achieve effective noise reduction.

For the same reason, it is favorable if the first wall is oriented transversely to an outlet opening of an outlet. This minimizes the proportion of sound waves that can propagate to the outlet.

For the same reason, it is favorable if the first wall is parallel or at an obtuse angle of at least 150° to the outlet tube.

The wall comprises a second wall which is oriented transversely to the first wall and connects to the first wall towards an inlet of the inlet pipe and in particular connects to form an edge. A sound reflection can, for example, also take place on the second wall, in particular if multiple reflections are present.

In particular, the second wall is a continuation of the inlet pipe towards the first wall. In particular, the second wall is designed in such a way that the sound propagation of reflected sound to the inlet is disturbed to a minimum. It can be advantageous if the second wall is designed to be at least approximately flat, in order in particular to realize an effective sound mirror design.

The wall has a third wall opposite the first wall and connecting the inlet tube to the outlet tube, the third wall being curved. The third wall is important for flow control. A pressure loss due to the flow deflection can be kept low by a curved design. Furthermore, sound waves, which are reflected in particular from the first wall, can also be reflected on the third wall in order to achieve effective noise reduction.

An inner radius of the third wall is larger than half a hydraulic diameter of the inlet pipe. This results in a flow deflection with minimized pressure loss. Flow deflection with minimized pressure loss can thus be achieved with great acoustic effectiveness in terms of noise reduction.

In one embodiment, a cross-sectional area (perpendicular to the direction of flow through the cross-sectional area) of the at least one flow element is larger at the sound mirror device than at an inlet and/or at an outlet. This provides an effective mirror surface for sound reflection, which can be achieved in particular without influencing the flow too much.

It is then provided, for example, that a cross-sectional area of the inlet pipe increases from an inlet to the sound mirror device and in particular increases monotonically. As a result, a high degree of reflection for sound waves can be achieved. For the same reason, it is favorable if a cross-sectional area of the outlet pipe decreases away from the sound mirror device towards an outlet and, in particular, decreases monotonically.

The inlet pipe has a first central longitudinal axis and the outlet pipe has a second central longitudinal axis, the first central longitudinal axis and the second central longitudinal axis intersecting at an intersection point which lies in the transition region within the at least one flow deflection element. An effective flow deflection with a low pressure loss can thereby be achieved, while at the same time a good degree of reflection for sound waves and thus an effective noise reduction can be achieved.

It is then particularly advantageous if the point of intersection lies between an inlet and a first wall of the sound mirror device. As a result, an effective flow deflection is achieved with a low pressure loss and a high degree of reflection for sound waves on the first wall is achieved.

For the same reason, it is favorable if the intersection point is between a second wall of the sound mirror device and an outlet. The second wall of the sound mirror device lies in particular transversely to the first wall.

The first central longitudinal axis and the second central longitudinal axis are advantageously oriented at an angle of at least 30° to one another.

In particular, the angle is in the range between 80° and 100° and is approximately 90°, for example.

Provision can be made for a sound-permeable flow guide device to be arranged on the sound mirror device, in particular if this is designed as a sound trough device. The flow guide device has in particular elements that guide the flow and are themselves not flow-permeable. An increased effective flow guidance and in particular deflection can then take place, with the sound reflection properties being retained.

In one embodiment, the at least one flow turning element is part of an elbow. As a result, the air-guiding device can be designed in an effective manner that is simple in terms of production technology.

In particular, it can be provided that the manifold at least partially surrounds a fan of the fan device. This results in a space-saving design, with flow paths being minimized.

The air guiding device is favorably connected to the blower device in a fluid-effective manner. Suction exhaust air can then be discharged via the air guiding device. In principle, however, it is also possible for the air duct device to be part of a cooling air duct for the suction device, for example.

In particular, the air guiding device is designed to discharge suction air and/or to supply suction air and/or to discharge cooling air and/or to supply cooling air.

The suction device is designed, for example, as a dry vacuum cleaner, or as a wet vacuum cleaner, or as a wet-dry vacuum cleaner or as a spray extraction device, wherein the suction device can be an independent device ("stand-alone device") or can be part of a cleaning machine. For example, the suction device is part of a manually operated or self-propelled cleaning machine such as a floor cleaning machine and, for example, a road sweeper or scrubbing machine.

Figur 1

eine perspektivische Darstellung eines Ausführungsbeispiels einer Saugvorrichtung als Nass-Trocken-Sauger in Form eines Sprühextraktionsgeräts;

Figur 2

eine Hinteransicht der Saugvorrichtung gemäß Figur 1 mit geöffnetem Gehäuse, wobei eine Gebläseeinrichtung gezeigt ist;

Figur 3

eine perspektivische Darstellung eines Ausführungsbeispiels eines Gebläses mit einem Krümmer und einem Strömungsumlenkelement;

Figur 4

eine Schnittansicht des Strömungsumlenkelements gemäß Figur 3;

Figur 5(a) bis (e)

verschiedene Formen für ein Strömungsumlenkelement. Nur die in den Figuren 5(d) und 5(e) dargestellten Strömungsumlenkelemente sind Teil der Erfindung;

Figur 6

die zu den Formen gemäß Figur 5 zugehörigen akustischen Transmissionsverluste (Kreise) und Druckverlustbeiwerte für eine Luftströmung (Quadrate);

Figur 7

ein weiteres Ausführungsbeispiel eines Strömungsumlenkelement.

In particular, an outlet of the outlet pipe of the at least one flow deflection element is arranged on a housing of the suction device or is in fluid communication with a housing outlet. This results in a simple structure with minimized flow losses. The following description of preferred embodiments, in conjunction with the drawings, serves to explain the invention in more detail, the scope of protection of which is determined exclusively by the following claims. Show it:

figure 1

a perspective view of an embodiment of a suction device as a wet-dry vacuum cleaner in the form of a spray extraction device;

figure 2

a rear view of the suction device according to FIG figure 1 with the housing open, showing a fan assembly;

figure 3

a perspective view of an embodiment of a fan with an elbow and a flow deflection element;

figure 4

a sectional view of the flow deflection element according to FIG figure 3 ;

Figure 5(a) to (e)

different forms for a flow deflection element. Only the ones in the Figures 5(d) and 5(e) flow deflection elements shown are part of the invention;

figure 6

those according to the forms figure 5 associated acoustic transmission losses (circles) and pressure loss coefficients for an air flow (squares);

figure 7

another embodiment of a flow deflection element.

An embodiment of a suction device, which in the figures 1 and 2 1 and labeled 10 there, is a vacuum cleaner having a base 12. The base 12 is mobile and has a left rear wheel 14 and a right rear wheel 16. FIG. Also on the base are a left front roller 18 and a right one Front roller 20 arranged. Left front roller 18 and right front roller 20 are pivotally positioned on base 12 .

On the base 12 there is also a handle unit 22 with a handle 24, through which in particular the suction device 10 as a whole can be pushed or pulled.

An absorbent body 26 is positioned on the base 12 and, in particular, is positioned so that it can be removed. The suction body 26 has a housing 28, in the interior 30 (same figure 2 ) Components of the suction device 10 is arranged.

The suction device 10 includes a fan device 32 ( figure 2 ) having a fan 34 and an associated motor, such as an electric motor, which drives one or more impellers of the fan 34 .

A suction air flow can be generated via the blower device 32 .

A connection 36 is arranged on the housing 28, to which a suction hose or a suction pipe can be connected. This connection 36 is in fluid communication with the blower device 32.

Components such as a dirt collection container and the like are arranged in the interior space 30 of the housing 28 .

In one embodiment, the suction device 10 is designed as a spray extraction device, by means of which liquid can be sprayed onto a surface to be cleaned and excess liquid can be sucked off.

Appropriate components are then arranged in the interior 30, such as in particular a tank for fresh water and optionally one or more tanks for chemical additives. Also in the interior 30 is a facility arranged to promote corresponding cleaning fluid for surface application.

When the suction device 10 is in operation, exhaust air is produced. This exhaust air is discharged via an exhaust air discharge device as part of an air duct device 38 .

During suction operation of the suction device 10, corresponding suction exhaust air is produced.

In principle, when the blower device 32 and/or other components of the suction device 10 are cooled, cool waste air is produced.

In one exemplary embodiment, the air guiding device 38 for the blower device 32 includes an elbow 40. The elbow 40 is fixed in the interior 30 in particular. For this purpose, it has, for example, mounting brackets 42a, 42b, via which it is fixed. Exhaust air from fan device 32 is coupled into manifold 40 and decoupled from it. It is ring-shaped, for example, and includes a ring channel 44 which surrounds the fan 34 .

A flow deflection element 46 is arranged on the manifold 40 and is designed in such a way that exhaust air can be discharged to the environment via a corresponding housing outlet.

In the case of the suction device 10, the housing outlet, which is figure 2 indicated at 48, on a rear side 50 of the housing 28, which is located at the rear wheels 16,18.

The flow deflection element 46 is designed in such a way that it is noise-reducing and the sound wave propagation is influenced accordingly.

The flow deflection element 46 has an inlet tube 52 and an outlet tube 54 ( Figures 3 and 4 ). The inlet tube 52 has an inlet 56 with an inlet port 58. The outlet tube 54 has an outlet 60 with an outlet port 62.

The flow deflection element 46 may be a separate piece from the annular passage 44 and then connected to the annular passage 44 or it may be integrally connected to the annular passage 44 .

The outlet 60 may form the housing outlet 48 or is in fluid communication with the housing outlet 48 .

In the described embodiment, both sound waves and fluid (suction exhaust) enter the inlet tube 52 and exit the outlet 60 of the outlet tube 54 is fluid and (at reduced intensity) sound. In other applications, however, it is also fundamentally possible for sound to be coupled into the inlet pipe 52 and out of the outlet pipe 54 , and for fluid to be coupled into the outlet pipe 54 and out of the inlet pipe 52 .

The flow deflection element 46 has a transition area 64 which lies between the inlet pipe 52 and the outlet pipe 54 . A flow deflection takes place at the transition area 64 .

A first central longitudinal axis 66 is assigned to the inlet pipe 52 . A second central longitudinal axis 68 is assigned to the outlet pipe 54 . The inlet tube 52 and the outlet tube 54 are transverse to each other to achieve flow deflection. The first central longitudinal axis 66 and the second central longitudinal axis 68 are transverse to one another. In particular, they lie at an acute angle of at least 30° to one another.

At the in the Figures 3 and 4 In the exemplary embodiment, the inlet pipe 52 and the outlet pipe 54 lie with their respective central longitudinal axes 66, 68 perpendicular to one another.

The first central longitudinal axis 66 and the second central longitudinal axis 68 intersect at a point of intersection 70. This point of intersection 70 lies within an interior space 72 of the flow deflection element 46. The point of intersection 70 lies in the transition area 64.

A sound mirror device 74 is arranged on the transition area 64 . The sound mirror device 74 serves to at least partially decouple the flow flowing through the flow deflection element 46 and sound waves in order to achieve a noise-reducing effect.

The sound mirror device 74 has a wall 76. The wall 76 is the transition wall from the inlet pipe 52 to the outlet pipe 54.

The wall 76 includes a first wall 78. The first wall 78 faces the inlet 56 and is oriented such that a relevant portion of the sound waves in the inlet tube 52 are reflected back through the first wall 78 in a direction toward the inlet 56 . this is in figure 4 indicated by reference numeral 80.

The first wall 78 connects to the outlet tube 54 and is an extension of the outlet tube 54 in the transition region 64.

The first wall 78 is essentially planar or has at most a slight curvature.

The first wall 78 is parallel or at a small acute angle to the inlet mouth 58 of the inlet 56.

At the in figure 4 shown embodiment (compare also figure 5 (e) ) the first wall 78 is at an acute angle 82 to the inlet opening 58 and is at an obtuse angle as the opposite angle to the acute angle 82 to the outlet pipe 54. A trough 83 ("sound trough") is formed as a result, which reflects sound on the first wall 78 with the formation of multiple reflections within the flow deflection element 46.

In one embodiment, acute angle 82 is approximately 20°. For example, it is in the range between 10° and 30°.

It can also be provided, as for example in Figure 5(d) The first wall is shown to be parallel to the inlet port 58 and parallel (i.e., an angle of 180°) to the outlet tube 54, respectively.

Intersection 70 is between inlet 56 and first wall 78; the first wall 78 is located behind the intersection 70 with respect to the inlet 56 and a corresponding direction of flow.

The wall 76 also includes a second wall 84 at the transition region 64. The second wall 84 adjoins the first wall 78 and is oriented transversely thereto. The second wall 84 then merges into the inlet pipe 52. In particular, the second wall 84 merges parallel into the inlet pipe 52 and is in particular a parallel continuation of the inlet pipe 52 into the transition area 64.

The second wall 84 is in particular oriented at least approximately parallel to the outlet opening 62 of the outlet 60 .

The second wall 84 is in particular flat.

In particular, an edge 85 lies between the second wall 84 and the first wall 78.

The wall 76 also has a third wall 86 which is opposite the second wall 84 and connects the inlet pipe 52 to the outlet pipe 54 there.

The third wall 86 is curved in order to minimize a pressure loss in the flow when flowing through the flow element 46 .

An inner radius R of the third wall 86 is larger than half the hydraulic diameter of the inlet pipe 52 in order to minimize the pressure loss.

It can be provided as in figure 3 shown that a cross-sectional area of the flow deflection element 46, the cross-sectional area being in particular perpendicular to the main direction of flow, is larger on the sound mirror device 74 and thus in the transition region 64 than in the inlet pipe 52 and/or the outlet pipe 54 by an enlarged area ("mirror area"). to provide for sound reflection.

For example, particularly in the transition area 64 , the corresponding cross-sectional area increases and particularly monotonously towards the first wall 78 starting from the inlet 56 and then decreases and particularly monotonously from the second wall 84 towards the outlet 60 .

A sound-permeable flow guide device 88 can be arranged on the sound mirror device 74 in particular on or in the vicinity of the first wall 78 and in particular in the trough 83 . The flow guide device 88 has one or more elements that are not permeable, in particular for the flow, but which are permeable to sound. This can result in a deflection of the flow, with sound reflection being able to take place.

For example, the cross-sectional shape of the inlet tube 52 and the outlet tube 54 may be round (such as circular or oval) or square. In figure 7 1, an embodiment of a flow diverter 90 is shown having an inlet tube 92 and an outlet tube 94 with square and rectangular cross-sections, respectively. A transition area 96 with a sound mirror device 74 is in turn arranged between these and basically functions in the same way as the flow element 46.

The suction device 10 according to the invention works as follows:
Exhaust air and in particular suction exhaust air from the blower device 32 is coupled into the flow deflection element 46 via the annular duct 44 and the inlet 56 . The flow is deflected at the flow deflection element 46 in accordance with the alignment of the second central longitudinal axis 68 to the first central longitudinal axis 66.

The flow deflection element 46 or 90 is designed in such a way that a corresponding pressure loss due to the flow deflection is minimized.

This is in the Figures 5 and 6 explained schematically.

In Figure 5(a) an example of a flow deflection element is shown, which is designed as a bent tube with curved transition surfaces. A point of intersection of central longitudinal axes of an inlet pipe 98a and an outlet pipe 98b lies on a wall of the pipe. An associated acoustic transmission loss 100 is shown in the diagram in FIG figure 6 and an associated pressure loss coefficient 102. The smaller the acoustic transmission loss 100, the greater the noise reduction. The smaller the pressure loss coefficient 102, the naturally lower the pressure loss due to the flow deflection.

In Figure 5(b) an embodiment is shown in which an inlet pipe 104a and an outlet pipe 104b are perpendicular to one another and no curved transition surfaces are provided.

How out figure 6 As can be seen, there is a high pressure loss coefficient here, that is to say this embodiment is unfavorable in terms of flow, with improved noise reduction being obtained.

In Figure 5(c) a variant is shown in which an inlet pipe 106a and an outlet pipe 106b are perpendicular to one another on one side without a curved transition surface and there is a curved transition surface opposite this side.

It turns out how figure 6 can be seen, according to the form Figure 5(b) approximately the same noise reduction but a reduced pressure drop.

In the embodiment according to Figure 5(d) , the third wall 86 is provided with the appropriate curvature as described above (the inner radius is greater than half the hydraulic diameter of the inlet tube 52). The pressure loss is further reduced with approximately the same noise reduction.

The sound mirror device 78 is formed in which the first wall 78 functions as a primary sound mirror which reflects sound waves so that the reflected sound waves cannot travel towards the outlet 60 .

There can also be multiple reflections of sound waves, particularly in the transition area 64 .

In the embodiment according to Figure 5(e) , which corresponds to the embodiment according to FIG. 4, the first wall 78 lies at an acute angle to the inlet opening 58 of the inlet 56 and a trough 83 is formed. It takes place Here's another noise reduction like out figure 6 can be seen, with minimized pressure loss. The first wall 78 continues to function as a primary sound mirror, with sound waves also being reflected toward, for example, the second wall 84 and being reflected from the second wall 84 toward the third wall 86, for example. As a result, the generation of noise from the suction device 10 is correspondingly reduced.

In the solution according to the invention with the sound mirror device 74 and the third wall 86, both an acoustic optimization and a fluidic optimization take place, with the acoustic optimization being decoupled from the fluidic optimization at least to a certain extent. As a result, an increased acoustic reflection effect can be achieved in the flow deflection element 46 with a relatively low pressure loss in the flow.

A flow deflection element 46 according to the invention was described in connection with the noise reduction in exhaust air from a suction device 10 . It is also possible that, alternatively or additionally, a corresponding deflection element is used to reduce noise in the supply air. Furthermore, it is alternatively or additionally possible that a corresponding flow deflection element is used for noise reduction in the supply air or exhaust air of an air cooling system.

Reference List

10

suction device

12

Base

14

left rear wheel

16

right rear wheel

18

left front roller

20

right front roller

22

handle unit

24

handle

26

absorbent body

28

Housing

30

inner space

32

fan device

34

fan

36

connection

38

air duct device

40

manifold

42a

mounting tab

42b

mounting tab

44

ring canal

46

flow diverter

48

housing outlet

50

back

52

inlet pipe

54

outlet pipe

56

inlet

58

inlet mouth

60

outlet

62

outlet mouth

64

transition area

66

first central longitudinal axis

68

second central longitudinal axis

70

intersection

72

inner space

74

sound mirror device

76

wall

78

first wall

80

sound reflection

82

acute angle

83

trough

84

second wall

85

edge

86

third wall

88

flow directing device

90

flow diverter

92

inlet pipe

94

outlet pipe

96

transition area

98a

inlet pipe

98b

outlet pipe

100

acoustic transmission loss

102

pressure drop

104a

inlet pipe

104b

outlet pipe

106a

inlet pipe

106b

outlet pipe

Claims (15)

1. A suction device comprising a fan device (32) for generating a suction air flow and an air conducting device (38) having at least one flow deflection element (46; 90) comprising an inlet tube (52; 92) and an outlet tube (54; 94), wherein the outlet tube (54; 94) is oriented transversely to the inlet tube (52; 92), wherein in a transitional area (64) between the inlet tube (52; 92) and the outlet tube (54; 94) there is arranged a sound reflector device (74) at which sound is reflected and/or sound is absorbed, wherein the sound reflector device (74) has a wall structure (76), which reflects sound, wherein the wall structure (76) comprises a first wall (78), which is arranged opposite an inlet (56) of the inlet tube (52; 92), wherein the wall structure (76) comprises a second wall (84), which is oriented transversely to the first wall (78) and adjoins the first wall (78) toward the inlet (56) of the inlet tube (52; 92), wherein the wall structure (76) has a third wall (86), which is arranged opposite the first wall (78) and connects the inlet tube (52; 92) to the outlet tube (54; 94), wherein the third wall (86) is curved, wherein the inlet tube (52; 91) has a first central longitudinal axis (66) and the outlet tube (54; 94) has a second central longitudinal axis (68), wherein the first central longitudinal axis (66) and the second central longitudinal axis (68) intersect one another at a point of intersection (70), which lies in the transitional area (64) within the at least one flow deflection element (46; 90),
   characterized in that an inner radius (R) of the third wall (86) is greater than half the hydraulic diameter of the inlet tube (52; 92).
2. The suction device as claimed in claim 1, characterized in that the wall structure (76) is oriented such that a reflection direction is oriented toward the inlet (56) of the inlet tube (52; 92), and/or in that the wall structure (76) is oriented such that a multiple sound reflection occurs within the at least one flow deflection element (46; 90).
3. The suction device as claimed in any one of the preceding claims, characterized by at least one of the following:

   • a trough is formed in the transitional area (64) by means of the first wall (78);

   • the first wall (78) is at least approximately flat;

   • the first wall (78) is oriented parallel to an inlet opening (58) of the inlet (56) or is oriented at a small acute angle less than 30° relative to the inlet opening;

   • the first wall (78) is oriented transversely to an outlet opening (62) of an outlet (60) of the outlet tube (54; 94);

   • the first wall (78) lies parallel or at an obtuse angle of at least 150° to the outlet tube (54; 94).
4. The suction device according to any one of the preceding claims, characterized in that the second wall (84) is an extension of the inlet tube (52; 92) to the first wall (78), and/or in that the second wall (84) is at least approximately flat.
5. The suction device as claimed in any one of the preceding claims, characterized in that a cross-sectional area of the at least one flow deflection element (46; 90) is greater at the sound reflector device (74) than at the inlet (56) and/or at the outlet (60).
6. The suction device as claimed in any one of the preceding claims, characterized in that a cross-sectional area of the inlet tube (52; 92) increases from the inlet (56) toward the sound reflector device (74) and in particular increases monotonically.
7. The suction device as claimed in any one of the preceding claims, characterized in that a cross-sectional area of the outlet tube (54; 94) decreases away from the sound reflector device (74) toward the outlet (60), and in particular decreases monotonically.
8. The suction device as claimed in any one of the preceding claims, characterized in that the point of intersection (70) lies between the inlet (56) and the first wall (78) of the sound reflector device (74).
9. The suction device as claimed in any one of the preceding claims, characterized in that the point of intersection (70) lies between the second wall (84) of the sound reflector device (74) and the outlet (60).
10. The suction device as claimed in any one of the preceding claims, characterized in that the first central longitudinal axis (66) and the second central longitudinal axis (68) lie at an angle of at least 30° to one another, and in particular in that the first central longitudinal axis (66) and the second central longitudinal axis (68) lie at an angle in the range between 80° and 100° to one another.
11. The suction device as claimed in any one of the preceding claims, characterized in that a sound-permeable flow guiding device (88) is arranged on the sound reflector device (74).
12. The suction device as claimed in any one of the preceding claims, characterized in that the at least one flow deflection element (46; 90) is part of a bend (40), and in particular in that the bend (40) surrounds a fan (34) of the fan device (32).
13. The suction device as claimed in any one of the preceding claims, characterized in that the air conducting device (38) is fluidically connected to the fan device (32), and in particular in that the air conducting device (38) is configured to discharge suction air and/or to feed suction air and/or to discharge cooling air and/or to feed cooling air.
14. The suction device as claimed in any one of the preceding claims, characterized by a configuration as a dry vacuum cleaner, or as a wet vacuum cleaner, or as a wet-dry vacuum cleaner, or as a spray extraction appliance.
15. The suction device as claimed in any one of the preceding claims, characterized in that the outlet (60) of the outlet tube (54; 94) is arranged on a housing (28) of the suction device or is fluidically connected to a housing outlet (48).

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